Case response Study Example | Topics and Well Written Essays - 500 words - 2

Response - Case Study Example Southwest’s growth strategy has always been to stay away from big cities characterized by delays in airports and instead concentrate on secondary options, which basically are less crowded. Such an approach as this has worked for the airline in the past allowing it to swiftly turn around its aircrafts in addition to flying more routes while at the same time staying realistically on time. Nevertheless, regardless of what looks like a cannot-lose situation, the airline could also be taking a huge gamble in LaGuardia; although a pretty secure one. Southwest is an airline that is known for its reliability on timely service, not only for its customers but also behind the scenes. The delay issues experienced in New York cannot just be underestimated-every one of the big 3 regional airports is frequently among the poorest performers especially in terms of punctuality-and will pose a great challenge for Southwest to surmount. Thus for Southwest to turn around the situation, and sustain its fast-turnaround approach of operation, it has its work already cut out. Whitney Eichinger-Southwest’s spokesperson has been on the record pointing out that the airline has proved critics wrong and succeeded in Philadelphia where everyone thought Southwest would run into difficulties (Heskett & Sasser Jr, 2013). Nevertheless, a move to LaGuardia is an exceptional opportunity that will not only open a huge population of business travelers but also the 8 million New Yorkers-some of whom may forego a ride to Long Island simply to snag low fares offered by the airline. This would especially be a catch if Southwest flies to Chicago and possibly Florida. The Airline’s fans in New York will especially be extremely happy since they will say goodbye to long and boring drives out the expansive Expressway of Long Island. In addition, Southwest will have access to a wide pool of weekday customers flying to such cities as Dallas, Toronto and Chicago. The airline will also increase its

Management by Objectives Essay Example | Topics and Well Written Essays - 250 words

Management by Objectives - Essay Example By setting objectives and completing them - the employee can enjoy a sense of accomplishment. Assuming a company has clearly conveyed a mission to be an embraceable vision for all employees from top to bottom; setting objectives with the employee and then letting the employee execute them gives the employee a feeling of team work and belonging. Peter Drucker first addressed MBO in 1954 in his book The practice of Management He later readdressed MBO in updated editions, including, Management: Tasks, Responsibilities, Practices originally published 1973. In the book in Drucker is always careful to stress the human element of management. (Drucker, 21973) He stresses the combined power of teamwork when strengths are emphasized. We are all managed in some way, whether it is by our parents, our jobs or our rules of society. A concrete example of management by objectives is from the company where I am employed. The company requires the manager to sit down with each associate and set goals for the year. Some goals are individually driven and some are business driven. For example, an individual goal might be to learn (or job shadow) a different position in the company, whereas a company goal might be to complete audit reports within a 180 days of the start. The individual goal is set by the associate; sometimes with the coaching of the manager, if needed.

Business Plan For Hakuna Matata Coffee Shop Marketing Essay

Business Plan For Hakuna Matata Coffee Shop Marketing Essay Hakuna Matata coffee shop is managed by a team of three individuals. It is a joint of each persons contribution and different ideas and skills which we have expressed our best opinions and interest to achieve the roles of Hakuna Matata. This is a business pursued by three individuals executing the opportunity of opening a coffee shop right in the city centre and to best coffee sellers in the city, we have got the opportunity to be not only the best coffee sellers but also to gain a market share and create market segment and most of all to build a customer relation, the customer could either be a walk in customer or a corporate customer. The major roles of Hakuna Matata are to become the best and most popular coffee shop in the area serving at least five hundred customers daily. The companys objective is to turn profits for every month of operations and maintain a gross profit margin of 60%. Hakuna Matata is specialized in coffee and other value added service is that it provides other beverages like various types of juices and sodas, milk, tea and distilled water bottles and snacks, as coffee would certainly be more attractive with chocolate cookies and some crackers to enjoy the coffee. Each member of the team contributed evenly towards the completion of the business plan. Grace Busara researched on the management, Halimafilsan researched on the financial plan while I researched more on the marketing plan for the business plan. There are a lot of different things that could help the coffee shop be more successful that is by efficient team work within the 3 of us, including our hired staff, these are the waiters and the security guard, which all play their roles, and are part of the coffee shop. Where the team runs smoothly, we make sure that that every process is been taken charge to work efficiently, that is by assigning the tasks equally, so that there is all equal inputting to the coffee shop. It is efficient to do work as a team than as an individual as team work comes up with different ideas and views; we get to know each other more, which could lead us to the success of our coffee shop. By team work the tasks are accomplished efficiently. PROCESS OF IDEA INITIATION Through our research we discovered that there are very few coffee shops in the market, most of which subscribe to the low cost leadership strategy, therefore, Hakuna Matata as an opportunity in the market and by using differentiation strategy it could gain a market share and create its market segment and build a strong customer base. There are tremendous interest in entrepreneurship in Tanzania, inspire of the country being a third world country; we managed to compile the resources needed for an entrepreneurship. We came up with three ideas of small scale business enterprise which would be booming in Tanzania for at least the next five years. The idea of coming up with a business of coffee shop was accepted by very all three members of the team, that is by considering all the positive factors of opening a coffee shop in the city which includes the opportunity which from our research we discovered that there are very less coffee shops in Dar es salaam city and in the market which subscribes to the low cost leadership strategy , where Hakuna Matata can get a chance to use the differentiation strategy whereby we can have an opportunity to gain a market share and also create market segment and build a strong customer base. The idea of a coffee shop business plan came up after a long thinking and analyzing the ideas and views of other proposed business plans which was contributed by the team members. The structure of the business is quickly evolved, like the experiences in the commercial market, that knows how many coffee shops exist in the city and the coffee shops surrounded near by our coffee shop location. It takes much more to operate a coffee shop as such a product, the idea of selling coffee as a beverage, we have to be able to continuously offer what customers are looking for, and therefore we should consider that there is no shortage of consumers for the coffee beverage, as there less coffee shops surrounded within the area. After a lot of brainstorming and doing research of opening a venture in a country like Tanzania, we had come up with several ideas in which we had three best choices, these are the coffee shop, garbage collection and event management planning, all these three ventures seemed interesting to us, but we found that the coffee shop would me more attractive the market. INDUSTRY AND COMPETITIVE The position of Hakuna Matata Coffee Shop fills in the market place, which will be on reason for its success; the coffee shops aim is to accomplish its target by being the best coffee sellers in the city, and to attract every customer by our coffee by providing the best coffee and providing good customer services. The position of Hakuna Matata Coffee Shop will carve out for itself in the market, as it will be opened the whole day till evening, our target customers will be all the surroundings offices, these are The Bank Of Tanzania, National Bank Of Commerce, Azania Bank Limited, FBME Bank Limited, CRDB Bank limited and many other banks surrounding our coffee shop, including also the walking customers and other offices surrounding the location of the coffee shop. Looking at the grid, Hakuna Matata Coffee Shop is the only concept which feels good about its role pf selling and preparing the best coffee in the city, which captures the families and children and all types of genders and ages. It also captures the advantage of relatively short preparation time, and coffee is served. Hakuna Matata Coffee Shop is well positioned to take advantage of the significant opportunities by expanding the industry of providing coffee beverages. The coffee consumption on the rise is dependent on the agricultural sector, whereby there are a lot of coffee farmers but a few coffee beverage sellers in the market, thus Hakuna Matatas bargaining power is high and thus it can acquire large volumes at a low price and the culture of drinking coffee has always been there in the market for example the local vendors who walk around with coffee in a kettle. Hakuna Matatas market is within the metropolitan area whereby the number of consumers is substantially high. Since Tanzania is a tropical area and the need for cols drinks is necessary, thus Hakuna Matata will make its beverages both cold and hot as Dar es salaam city is has a moderate temperature above 28 degrees centigrade, therefore various types of other beverages will be offered, such as soda, tea, distilled bottle water, tea, milk and different flavors of juices. In this same segment the customers are further divided into female consumer who prefer milk tea and coffee which is not strong while the male clients prefer black coffee or coffee that is very strong. Hakuna Matata is targeting two main customers, one is the fixed customers which consists of the office workers, shop keepers, college and university students, whereby this group is the most liquid and consume large amounts of coffee per day, since our fixed consumers have limited time, Hakuna Matata will have store the coffee in the privately owned utensils which can will make it easier to the customers to leave with them as take away. The second target groups are the mobile consumers, these are the daily and new consumers, this group consists of individual who do not have a fixed location such as shoppers, pedestrians, walk in customers and many more. Our competitors are classified into two categories, that is the first priority competitors and second priority competitors, the first priority competitors are the ones which we have used the differentiation strategy, this includes serving coffee at the best quality level. The second priority customers are using the low cost and no frill strategy to gain a market share; this includes the local coffee makers and the street vendors in the city. Currently the completion for coffee as a beverage amongst coffee sellers is not fierce, whereby the seller can enter and leave the market rapidly. Coffee beverage selling is a relatively new industry in Tanzania, as it is not in the culture of Tanzania compared to tea, therefore the industry is in the state of flux, with less market leaders and nationally known providers or widely recognized brands as the other coffee sellers provide coffee which does not meet the taster and the requirements of the consumers. PRESENTATION EXPERIENCEANALYSIS Presetting a business plan helps us and the user to identify the objective of the business and analyze it in a critical manner; it helps us to focus in the feasibility of the business and to identify the chances of growth and success. It also enables to manage the business too accordingly and with a positive attitude. The presentation of the business plan is a way of communicating with your business which defines the purpose and the competition of the business and the management; it identifies the intention of creating a business into reality. it is important to present a business plans as it is useful if we are applying for a bank loan to fund our coffee shop, or trying to get an investor who can come and invest in our coffee shop, this could either be our friends and relatives or the government. The business plan presentation is useful if we are fund raising in general. No one will give us money nor fund as we have not planned your business plan positively as the business plan consists of how much money we need and for what purposes of the business, the marketing plan, the sales strategies, the profit projection. A business plan guides us on how we can raise capital and gives us a road map so we should know where the business is building up and growing. By presenting the business plan it is easy to identify the strength of the coffee shop business, as the demand for coffee increases daily due to our location which is in the city centre, this will also enable us to know who our customers are. We also noticed that coffee beverage is a push product as Tanzania does not have the culture of drinking coffee, though our target customers are mainly, the corporate offices, banks and other large organizations in the city, as coffee could become seasonal due to the weather in Dar es salaam which is humid through out the year. We also fear new entrants in the coffee market which could deploy our venture, although we have fewer competitors. It is very important to plan the business before executing it to reality, this will make us know how the business is going to survive and grow within the specific time, a business without a plan would certainly fail in a short period of time, hence it also enables us to achieve our targets and business goals. ALTERNATIVE SCENARIO Our start up capital is 20 million Tanzania shillings, where each member has contributed 5 million and another 5 million will be taken from FBME Bank limited as a loan. Our assumptions are that we assume a slow growth without recession taking place in Tanzania, we assume that there will be no unforeseen changes in the public health perceptions about our coffee and beverages that we offer to the consumers, we also assume that our finances are going to be sufficient to maintain our projected financial plan and we also assume that it will continue to grow as production increases. Besides coffee shop we also had different ideas on creating a small scale enterprise, researched the market and the environment surrounding us, whereby a lot of brain storming was done by all the three members of the group and came up with three different scenarios which we could create business plans were coffee shop business plan, event management business plan and garbage collection business plan, whereby our last and final choice was the coffee shop business plan. One of the ideas was to open a garbage collection, we researched and compiled the information which was to target the commercial and residential market, we came to know that the competitors are going to be low but the legal and financial requirements will not be able to cop up with our minimum amount of our startup capital. We came to know that there is a political risk in this business as the ministry of health had to approve the standard of our venture. We had come up with three different ideas amongst the coffee shop and garbage collection; we also had done our research on event management. From our research we learnt that event management planning will need a small start up capital and even the costs would be low, the marketing would be much more easier, planning the financials was depending on the event, being three of us it would be difficult to run an event, where a large labor force is required for this venture in order for this business to run well and the even to be successful, due to the large labor turnover, as since it is a new business we would be able to pay our staff. Event management being a high profit margin industry, as everyone would likes celebrations, and a well organized event the venture is highly profitable. This venture requires professional skills and high degree of energy for the execution of the event, it also requires communication, strong networking to be known in the market, excellent public relation is very important and we all three lack experience in events as we do not expertise art and creation of the venues. This two mentioned scenarios, disapproved us from choosing to open the ventures, therefore we choose coffee shop as a venture, as we all had the passion of selling coffee and making coffee in different methods and styles and from our knowledge and experience we finally concluded by opening the coffee shop in the city centre. USEFULNESS OF A BUSINESS PLAN As time passes the business develops. The business plan is a very useful and strategic tool which enables the company to achieve its target and goals within a given period of time, business plans are believed to be attainable if followed accordingly and by planning to reach the targets. The business plan compromises the plan on how to achieve the goals and targets including the management team, the usefulness of the business plan are that it includes the financial plans indicating the profit margin for each year respectively. It also shows the break even analysis. The business plan includes the marketing plan, this enables on how our coffee shop will be useful to the population surrounding the shop The financial plan section is the most important part of the business plan which shows how the ideas are viable and it is a key component in determining wither the business plan is going to be able to attract any investment in the planning of the coffee shop. The financial plan section compromises of financial statements which are divided into the income statement, the cash flow projection and a balance sheet including a brief explanation and analysis of each statement, therefore, the financial plan guides the growth and development of the coffee shop. When starting a venture, seeking additional capital for the coffee shop and setting new business process incase of the coffee shop fails to run, we need to write a plan detailing on how we will mange the resources and requirements which also includes the marketing decisions, the financial projections, a trend of the production demands and also personal needs. The plan reflects on three main constituencies that is the customer, the investor and the producer. A business plan has to be presentable to convince the venture capitalist, which should consists of a number of related issues that relate to the factors such as the critical success of the coffee shop, the human factor, the opportunity, the context and the possibilities of risk and reward, by analyzing these issues a business plan illustrates how the enterprise will seize the opportunity to enter the market and how its stand out amongst its competitors and how it plans to maintain a continuing growth trend. The investor or the per son who would be interested in captivating the coffee ship should see the level of detail before making any financial decision to the new coffee shop. OTHER AREAS For a business plan to be successful and profitable we clearly need to understand the firms customers and strength and completion in the market, it is the owners and shareholders who have to understand the behaviors of the customers and the strength and weaknesses. We should also have the ability to foresight and plan the future of Hakuna Matata Coffee Shop and its future expansion strategies. When it comes to the expansion of the coffee shop we need to know the financial plan which will enable us to how the coffee shop is growing. In order to operate the coffee shop more effectively we will have to manage the bargaining power of the suppliers and to manage the bills and also customer complains, as we need to take this matter into consideration in a calm manner and not to chase away the consumers. We have to show the consumers that we not only serve the best coffee but also our services are to a high standard of customer expectation.

RIP American Motors: 1954-87 :: Free Essays Online

RIP American Motors: 1954-87 In the early 1900's, automobile manufacturing was a growing business. Independent automakers such as Auburn, Hudson, Nash, and Studebaker served a focused market, catering to small car drivers, not covered by the "Big Three" makers: Ford, General Motors, and Chrysler. Many of these independent automakers saw their last days during the Great Depression. After World War II, there was just a handful left. American Motors was formed by the merger of two of these independents: Nash and Hudson. Nash President George Mason and Vice President George Romney saw the inevitable, to survive, the independents had to merge. Mason first talked to Packard who could not agree to a merger. After Mason tired of Packard's reluctance to join, he approached his second choice, Hudson. Hudson President, A.E. Barrit saw that Hudson was quickly losing money and decided that a merger would be the best course of action. On May 1, 1954, Nash and Hudson joined, forming American Motors. (Foster 11) Mason was named chairman of the board, president, chief executive officer, and general manager. His assistant George Romney was named vice president, and Barrit became a director of the company. For the first year of production, all of the old Hudsons were dropped, either for being dated or just not doing well in the market. The all-new Hudsons were based on existing Nash bodies with design features to keep them different. All Hudson production was also moved out of Detroit into Nash's main plant at Kenosha, Wisconsin. In October, six months after the merger, Mason fell ill and unexpectedly died. The next day, Romney assumed all of his titles and responsibilities. At the end of 1955, American Motors closed its West Coast plant at El Segundo, California, and moved all production to Kenosha. This move increased production, but still ended the year with a loss of $6.9 million. (Foster 18) The 1956 model year brought out a new car, The Rambler. This was not a new name, but the car came out with no mention of Nash or Hudson. The press raved the new Rambler with its improved power, larger interior, and smoother steering. The rest of the American Motors line however, still carried the dated styles of 1952.

English Term Paper Essay

I. Introduction: Technology is people using tool, resources, and processes to solve problems or extend their capabilities. Technology has existed as long as people have existed. It is always changing and never tends to stand still. Through the use of technology, a student can easily get the corresponding feedback for his works. He makes use of technology in getting correct answers and start solving again. The integration of technology results to a more student-centered education. It serves as an instrument on gaining access and manipulating information where students become actively involved in the process of learning. It is very obvious that the people especially students of our generation are now attached to computers, specifically to those computer games that are famous nowadays. Instead of reading books or browsing the net for school reports, we can’t deny that student tends to go online or play the computer first. Computer games are video games played on a general-purpose personal  computers rather than a dedicated video game console or arcade machine. It is very evident that a lot of students are developing bad habits that are caused by those computer games with violence as the main theme of the game. Most of the time, students keep on spending large amount of time in front of the computer doing unnecessary things, specifically playing computer games which usually leads into being a computer addict. Addiction is the continued use of a mood altering substance or behavior despite adverse dependency consequences. Computer games addiction has no physical component or objective diagnosis, but many of the consequences are similar to alcoholism or drug addiction. This type of addiction mostly affects the behavior of a person which may lead to a more serious case. Computer games addict mostly isolate themselves from normal human contacts. They change a lot and begin to ignore the others. An addict sometimes gets bankrupted or broke due to spending a lot for their vices. They also begin to be detached from their own families and violence is being spotted already. II. Objectives and Questions: This research aims to: 1. Know different computer games that the students are getting addicted to. 2. Identify the effects of computer games to the studies of the students. 3. Provide or suggest different ways to avoid computer games. This research aims to answer the following questions: 1. What are the effects of computer games to the studies and characters of the students? 2. What are the possible solutions that can help the students avoid computer games? 3. What are the different computer games that the students are getting addicted to? 4. What are the ways to prevent computer addiction? 5. Why can’t students resist playing computer games? III. Significance of the Study: In this study, we can help the students know the effects of computer games to their study habits and also their daily lives. Also to let them know the effects of getting addicted to it, the time they spent in front of the computer may be reduced. The time for more productive activities will be recognized and study habits may be more successful. We also wish to let people learn in this study to control their computer addiction and let them have the knowledge to know the advantages and disadvantages of computer games. IV. Scope and Delimitation This study only covers students from the high school department of St. Mary’s College of Meycauayan, school year 2012 – 2013. Our group will be doing surveys from random students of the said department. This research only aims to help students reduce or prevent their unwavering love for those computer games which somehow distracts their study habits. We do hope that this research could help them. V. Terminologies 1. Technology – a capability given by the practical application of knowledge 2. Addiction – is the continued use of a mood altering substance or behavior despite adverse dependency consequences, or a neurological impairment leading to such behaviors. 3. D.O.T.A – Defense of the Ancients (DotA) is a multiplayer online battle arena mod for the video game Warcraft III: Reign of Chaos and its expansion, Warcraft III: The Frozen Throne, based on the â€Å"Aeon of Strife† map for StarCraft. The objective of the scenario is for each team to destroy the opponents’ Ancients, heavily guarded structures at opposing corners of the map. 4. Violence – the intentional use of physical force or power, threatened or actual, against a person, or against a group or community, that either results in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment or deprivation. Chapter II: Review of Related Literature I. Related Literature â€Å"Nowadays, Googling and Facebooking are the most common daily activities in our society. 16 out of 16 first year students surveyed by the researchers at Mapua Institute of Technology said that they always do Googling and Facebooking. The huge time that collegestudents waste increases.Computer Addiction 4Students aside from doing school project also try to update with  the celebrity gossips andvisit the sites where they can easily find news about favorite celebrities and reading magazines.Sometimes they are obsessed with glamorous life of celebrities that make them forget what they should do as students. The addicted students always feel anxious or depressed when their computer time is shortened and they also easily become angry when being disturbed(Derevensky & Gupta, 2004). Students tend to surf the net first and gather many info on news,celebrity gossip, and organizing data, which is too much that not all of the information can beused (Derevensky & Gupta, 2004). Internet addiction disorder refers to the problematic use of the Internet, including thevarious aspects of its technology, such as electronic mail (e-mail) and the World Wide Web(American Psychiatric Association, 2000). Students nowadays do have a known disorder, whichis the IAD (Internet Addiction Disorder). They may not be able to know that they have thisdisorder until they realized that playing or using computer is more prioritized than doing schoolworks. Students get so obsessed with online gaming like Defense of the Ancient, Left for Dead,Cabal, etc. that they tend to sacrifice their academic sides just to go to computer shops and play,not noticing the time while using the computer (Sharples, 2009;Self-Help: Computer Addiction,2008). According to the survey conducted by the researchers at Mapua Institute of Technology, 9out of 16 students are at risk of being hooked with the computer games and have academicfailure for the first quarter of school year 2009-2010. They make conscious efforts just to be withtheir computers and continue failing. Also for the fact that they miss events or opportunities withfamily and friends also with non-computer related tasks because of the time spent on theComputer Addiction 5computer.† â€Å"Computer games addiction is not a physical disease or mental illness. It does not have an entry of its own in the DSM-IV. It describes a behavior that has become increasingly familiar with the rise of computer game popularity. A person with this type of addiction sets aside practically all other activities in favor of playing computer games almost endlessly.†

4 Expert PSAT Calculator Tips + Approved Calculators

4 Expert PSAT Calculator Tips + Approved Calculators SAT / ACT Prep Online Guides and Tips PSAT math can be intimidating, so it would be nice to be able to have some computerized help. But can you use a calculator on the PSAT? Yes, you can, though only on the second of the two Math sections on the PSAT.But what kind of calculator can you use, and when does it make sense to use a calculator on the PSAT? Read on for the complete list of approved calculators for PSAT test day and our top tips for using your calculator effectively. Can You Use a Calculator on the PSAT? Like the SAT, the PSAT has four sections: Reading, Writing, Math (No Calculator), and Math (Calculator). The No Calculator Math section is 25 minutes long, and has 17 questions, while the Calculator section is 45 minutes long and has questions. As the name suggests, the only time during the PSAT where you can use your calculator is on thefinal Calculator mathsection. According to College Board, most questions on the Calculator Math section can be answered without using a calculator, but a calculator could be useful on some questions. Translated from the College Board's cautious official language: you absolutely should use a calculator when it’s called for to make your life easier, but don’t over-complicate questions by using a calculator when it would be quicker to solve by hand. For example, it’s faster (and presents lower chances of error) to use your calculator to multiply 34 x 174. However, it’s much faster to solve an equation like 3x + 4y = 17, 4x + 8y = 26 by hand than to use your graphing calculator to do it. Approved Calculators for PSAT Test Day The College Board allows three types of calculators on the PSAT: four-function calculators, scientific calculators, and graphing calculators. Four-function calculators are so-called because they can basically just do four things: add, subtract, multiply, and divide. Although you could theoretically use just a four-function calculator on the PSAT, it's not recommended, most likely because four-function calculators usually lack useful features like parentheses and entry lines. The only advantages of four-function calculators are that they tend to be relatively inexpensive and take up less space. But honestly, the disadvantages of not being able to see what you just entered into the calculator far outweigh the benefits. All scientific calculators are permitted for use on the PSAT. A scientific calculator has all the features of a four-function calculator plus a few other useful things. Key functions included in all scientific calculators are parentheses, pi, and trigonometric functions, as can be seen below: AJC1/Flickr Parentheses in particular are great because you can use them to make sure your calculations happen in the right order. For example, ((15 x 19) – (13/2)) /100 is a whole lot easier to enter in all at once with parentheses, instead of having to break it up into its individual parts and then re-use the parts; every extra calculation entry you do introduces the chance of more error. The final type of calculator you can bring to the PSAT is a graphing calculator. Graphing calculators are great because they will definitely have features like entry lines as well as everything a scientific calculator has. They can also be helpful in visualizing solutions to linear equations – for instance, if you want to find out where the two equations cross, you can just look at the graph to get the coordinates The only problem with graphing calculators is that their multifunctionality can trick students into using them when not using a calculator would be faster. Avoid this trap by using a graphing calculator as you take practice tests and challenging yourself to question each time you use the calculator if it’s really necessary, or if it’s taking up more time than it’s saving. Unlike with scientific calculators, not all models of graphing calculator are allowed under the PSAT calculator rules. Below is a chart of acceptable PSAT graphing calculators, sorted by brand. Casio Hewlett-Packard Radio Shack Sharp Texas Instruments Other Brands FX-6000 series HP-9G EC-4033 EL-5200 TI-73 Datexx DS-883 FX-6200 series HP-28 series EC-4034 EL-9200 series TI-80 Micronta FX-6300 series HP-38G EC-4037 EL-9300 series TI-81 Smart2 FX-6500 series HP-39 series EL-9600 series (stylus not permitted) TI-82 FX-7000 series HP-40 series EL-9900 series TI-83/TI-83 Plus FX-7300 series HP-48 series TI-83 Plus Silver FX-7400 series HP-49 series TI-84 Plus/TI-84 Plus T FX-7500 series HP-50 series TI-84 Plus CE/TI-84 Plus CE-T FX-7700 series HP Prime TI-84 Plus Silver FX-7800 series TI-84 Plus C Silver FX-8000 series TI-85 FX-8500 series TI-86 FX-8700 series TI-89 FX-8800 series TI-89 Titanium FX-9700 series TI-Nspire/TI-Nspire CX FX-9750 series TI-Nspire CAS/TI-Nspire CX CAS FX-9860 series TI-Nspire CM-C/TI-Nspire CM-C CAS CFX-9800 series TI-Nspire CX-C CAS CFX-9850 series CFX-9950 series CFX-9970 series FX 1.0 series Algebra FX 2.0 series FX-CG-10 (PRIZM) FX-CG-20 Want to improve your PSAT score by 150 points? We have the industry's leading PSAT prep program. Built by Harvard grads and SAT full scorers, the program learns your strengths and weaknesses through advanced statistics, then customizes your prep program to you so that you get the most effective prep possible. Check out our 5-day free trial today: Avoid These PSAT Calculators Some calculators, like TI-92 Plus or Voyage 200, are banned from the PSAT because they violate College Board PSAT calculator guidelines. Most of these guidelines are common sense, like that you can’t use a calculator that makes noise or a calculator that can access the Internet. A few of the other qualifications, though, are less obvious, like the fact that you can’t use a calculator that requires an electrical outlet. If your calculator meets any of the following criteria, you cannot use it on the PSAT: It’s part of a portable/handheld computer, laptop, electronic writing pad, or pocket organizer. Shockingly, you can't use your computer while taking the PSAT. It has QWERTY (i.e., typewriter) keypads as part of hardware or software (e.g., TI-92 Plus, Voyage 200). You also can’t use any â€Å"hardware peripherals† with an otherwise approved calculator (e.g. an external keyboard or LCD screen) It has pen-input/stylus/touch-screen capability (e.g., Palm, PDAs, Casio ClassPad) It has wireless or Bluetooth capability It paper tapes It can "talk" (terrifying) or make noise It requires an electrical outlet It can access the Internet It has cell phone capability or audio/video recording capability. No using your cellphone calculator on the PSAT! It has a digital audio/video player It has a camera or scanning capability No external view screens allowed on yourPSAT calculator! (Joe Haupt/Flickr) 4 PSAT Calculator Tips Now that you know what your options are for approved calculators for PSAT testing, let's go through a few key tips to help you use your calculatoreffectively on test day. Tip 1: Bring an Approved Calculator to the Test It’s better to have a calculator you can use and end up not needing it than to need a calculator and not have one. The same thing goes for making sure it’s an approved calculator; there’s no point in bringing a calculator with you that you can’t use. Tip 2: Be Familiar With Your Calculator One of the main reasons to use a calculator is that it enhances your speed and accuracy on the test. If you’re using a calculator you’ve never used before, you’ll be slower and more prone to errors, no matter how fancy the calculator is. Avoid test-day peril by using the calculator you plan to use on the PSAT for your everyday schoolwork and homework as much as possible. That way, when PSAT time comes, you’ll be comfortable with your calculator. Tip 3: Check the Calculator's Entry Line When you’re doing calculations during the test, it can be easy to get caught up in the rush to finish the test in time and accidentally hit "8" instead of "5," or "x" instead of "-". To limit the impact of these errors on you, double check the entry line before hitting â€Å"enter† to make sure you haven’t entered in the wrong number or operation. Double-checking the entry line is particularly important if you’re not using a graphing calculator that keeps a running log of all the calculations you’ve done. Tip 4: Know When Not to Use Your Calculator Especially if you have a graphing calculator, it can seem like the easier thing to do is to let the calculator work for you. Meticulously entering in an equation into the calculator and getting it to solve it for you, however, can take way more time than just doing it by hand would. This doesn’t mean you shouldn’t use the calculator at all; rather, use it as a supplement to your skills, rather than as a replacement. Be warned,you shouldn't rely on calculator apps to do the hard work for you. PSAT proctors have the right to inspect your calculator and delete all programmed apps on there, and if you’d grown accustomed to using apps to solve problems, you’ll be in hot water. Hot water: beautiful to watch spewing from a geyser, less beautiful to be in. What’s Next? Now that you've gotten your calculator figured out, what's left to do? Only to learn what a perfect PSAT score is and how to get it, naturally. Ready to get into the details of what you'll be tested on when you take the PSAT? We discuss what's covered (and what's not) in our complete guide to the PSAT. Find out when you can take the PSAT with our up-to-date PSAT test dates article. Want to improve your SAT score by 160 points or your ACT score by 4 points?We've written a guide for each test about the top 5 strategies you must be using to have a shot at improving your score. Download it for free now:

Maximum Likelihood Estimation Examples

Maximum Likelihood Estimation Examples Suppose that we have a random sample from a population of interest.  We may have a theoretical model for the way that the population is distributed.  However, there may be several population parameters of which we do not know the values.  Maximum likelihood estimation is one way to determine these unknown parameters.   The basic idea behind maximum likelihood estimation is that we determine the values of these unknown parameters.  We do this in such a way to maximize an associated joint probability density function or probability mass function.  We will see this in more detail in what follows.  Then we will calculate some examples of maximum likelihood estimation. Steps for Maximum Likelihood Estimation The above discussion can be summarized by the following steps: Start with a sample of independent random variables X1, X2, . . . Xn from a common distribution each with probability density function f(x;ÃŽ ¸1, . . .ÃŽ ¸k).  The thetas are unknown parameters.Since our sample is independent, the probability of obtaining the specific sample that we observe is found by multiplying our probabilities together.  This gives us a likelihood function L(ÃŽ ¸1, . . .ÃŽ ¸k)   f( x1 ;ÃŽ ¸1, . . .ÃŽ ¸k) f( x2 ;ÃŽ ¸1, . . .ÃŽ ¸k) . . .  f( xn ;ÃŽ ¸1, . . .ÃŽ ¸k) ÃŽ   f( xi ;ÃŽ ¸1, . . .ÃŽ ¸k).Next, we use Calculus to find the values of theta that maximize our likelihood function L.  More specifically, we differentiate the likelihood function L with respect to ÃŽ ¸ if there is a single parameter.  If there are multiple parameters we calculate partial derivatives of L with respect to each of the theta parameters.To continue the process of maximization, set the derivative of L (or partial derivatives) equal to zero and solve for theta.We can then use o ther techniques (such as a second derivative test) to verify that we have found a maximum for our likelihood function. Example Suppose we have a package of seeds, each of which has a constant probability p of success of germination.  We plant n of these and count the number of those that sprout.  Assume that each seed sprouts independently of the others.  How do we determine the maximum likelihood estimator of the parameter p? We begin by noting that each seed is modeled by a Bernoulli distribution with a success of p. We let X be either 0 or 1, and the probability mass function for a single seed is f( x ; p ) px (1 - p)1 - x.   Our sample consists of n  Ã‚  different Xi, each of with has a Bernoulli distribution.  The  seeds that sprout have Xi 1 and the seeds that fail to sprout have Xi 0.   The likelihood function is given by: L ( p ) ÃŽ   pxi (1 - p)1 - xi We see that it is possible to rewrite the likelihood function by using the laws of exponents.   L ( p )   pÃŽ £ xi (1 - p)n - ÃŽ £ xi Next we differentiate this function with respect to p.  We assume that the values for all of the Xi are known, and hence are constant.  To differentiate the likelihood function we need to use the product rule along with the power rule: L ( p )   ÃŽ £ xip-1 ÃŽ £ xi (1 - p)n - ÃŽ £ xi - (n - ÃŽ £ xi )pÃŽ £ xi (1 - p)n-1 - ÃŽ £ xi We rewrite some of the negative exponents and have: L ( p ) (1/p) ÃŽ £ xipÃŽ £ xi (1 - p)n - ÃŽ £ xi - 1/(1 - p) (n - ÃŽ £ xi )pÃŽ £ xi (1 - p)n - ÃŽ £ xi [(1/p) ÃŽ £ xi  - 1/(1 - p) (n - ÃŽ £ xi)]ipÃŽ £ xi (1 - p)n - ÃŽ £ xi Now, in order to continue the process of maximization, we set this derivative equal to zero and solve for p: 0 [(1/p) ÃŽ £ xi  - 1/(1 - p) (n - ÃŽ £ xi)]ipÃŽ £ xi (1 - p)n - ÃŽ £ xi Since p and (1- p) are nonzero we have that 0 (1/p) ÃŽ £ xi  - 1/(1 - p) (n - ÃŽ £ xi). Multiplying both sides of the equation by p(1- p) gives us: 0 (1 - p) ÃŽ £ xi  - p (n - ÃŽ £ xi). We expand the right hand side and see: 0   ÃŽ £ xi  - p ÃŽ £ xi  - p n pÃŽ £ xi   ÃŽ £ xi - p n. Thus ÃŽ £ xi p n and (1/n)ÃŽ £ xi   p.  This means that the maximum likelihood estimator of p is a sample mean.  More specifically this is the sample proportion of the seeds that germinated.  This is perfectly in line with what intuition would tell us.  In order to determine the proportion of seeds that will germinate, first consider a sample from the population of interest. Modifications to the Steps There are some modifications to the above list of steps.  For example, as we have seen above, is typically worthwhile to spend some time using some algebra to simplify the expression of the likelihood function.  The reason for this is to make the differentiation easier to carry out. Another change to the above list of steps is to consider natural logarithms. The maximum for the function L will occur at the same point as it will for the natural logarithm of L.  Thus maximizing ln L is equivalent to maximizing the function L. Many times, due to the presence of exponential functions in L, taking the natural logarithm of L will greatly simplify some of our work. Example We see how to use the natural logarithm by revisiting the example from above.  We begin with the likelihood function: L ( p )   pÃŽ £ xi (1 - p)n - ÃŽ £ xi . We then use our logarithm laws and see that: R( p ) ln L( p ) ÃŽ £ xi ln p (n - ÃŽ £ xi) ln(1 - p). We already see that the derivative is much easier to calculate: R( p ) (1/p)ÃŽ £ xi - 1/(1 - p)(n - ÃŽ £ xi) . Now, as before, we set this derivative equal to zero and multiply both sides by p (1 - p): 0 (1- p ) ÃŽ £ xi -  p(n - ÃŽ £ xi) . We solve for p and find the same result as before. The use of the natural logarithm of L(p) is helpful in another way.  It is much easier to calculate a second derivative of R(p) to verify that we truly do have a maximum at the point (1/n)ÃŽ £ xi   p. Example For another example, suppose that we have a random sample X1, X2, . . . Xn from a population that we are modelling with an exponential distribution.  The probability density function for one random variable is of the form f( x ) ÃŽ ¸-1 e -x/ÃŽ ¸ The likelihood function is given by the joint probability density function. This is a product of several of these density functions: L(ÃŽ ¸) ÃŽ   ÃŽ ¸-1 e -xi/ÃŽ ¸   ÃŽ ¸-n e -ÃŽ £ xi/ÃŽ ¸    Once again it is helpful to consider the natural logarithm of the likelihood function.  Differentiating this will require less work than differentiating the likelihood function: R(ÃŽ ¸) ln L(ÃŽ ¸) ln [ÃŽ ¸-n e -ÃŽ £ xi/ÃŽ ¸] We use our laws of logarithms and obtain: R(ÃŽ ¸) ln L(ÃŽ ¸) - n ln ÃŽ ¸Ã‚   -ÃŽ £xi/ÃŽ ¸ We differentiate with respect to ÃŽ ¸ and have: R(ÃŽ ¸)   - n / ÃŽ ¸Ã‚   ÃŽ £xi/ÃŽ ¸2 Set this derivative equal to zero and we see that: 0 - n / ÃŽ ¸Ã‚   ÃŽ £xi/ÃŽ ¸2. Multiply both sides by ÃŽ ¸2 and the result is: 0 - n ÃŽ ¸Ã‚   ÃŽ £xi. Now use algebra to solve for ÃŽ ¸: ÃŽ ¸ (1/n)ÃŽ £xi. We see from this that the sample mean is what maximizes the likelihood function.  The parameter ÃŽ ¸ to fit our model should simply be the mean of all of our observations. Connections There are other types of estimators.  One alternate type of estimation is called an unbiased estimator.  For this type, we must calculate the expected value of our statistic and determine if it matches a corresponding parameter.