samples of size n are selected from each of k populations. It will be assumed that the k populations are independent and normally distributed with means [pic][pic] and common variance [pic]. We wish to derive appropriate methods for testing the hypothesis: [pic] [pic] [pic] at least two of the means are not equal. Table 1 K random samples | |Population | | |
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Stock Market Prices Do Not Follow Random Walks: Evidence from a Simple Specification Test Andrew W. Lo A. Craig MacKinlay University of Pennsylvania In this article we test the random walk hypothesis for weekly stock market returns by comparing variance estimators derived from data sampled at different frequencies. The random walk model is strongly rejected for the entire sample period (19621985) and for all subperiod for a variety of aggregate returns indexes and size-sorted portofolios. Although
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Fundamentals of Hypothesis-Testing Methodology Hypothesis testing typically begins with a theory‚ a claim‚ or an assertion about a particular parameter of a population. Some of them are: • The Null and Alternative Hypotheses The hypothesis that the population parameter is equal to the company specification is referred to as the null hypothesis. A null hypothesis is often one of status quo and is identified by the symbol H0. Whenever a null hypothesis is specified‚ an alternative hypothesis is also
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Hypothesis testing using the binomial distribution Chapter assessment 1. Sweets called “Scruffies” are sold in packets of 18. Scruffies come in a variety of colours‚ and market research shows that red is the most popular. Scruffies are packed randomly‚ and on average 25% are red. (i) Find the probability that a packet contains no more than 6 red Scruffies. [2] (ii) Find the probability that a packet contains exactly 4 red Scruffies. [2] Because of a fault in the packing machine
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as shown in the ClassPak. The statement in parentheses refers to the Alternative Hypothesis for each. 5. On average IU students go out 2.5 nights or more per week. (The alternative hypothesis is that IU students go out less than 2.5 times per week.) Ho: μNights >= 2.5 Ha: μNights < 2.5 6. On average IU students drink exactly 5 1/2 drinks in an average night out. (The alternative hypothesis is that IU students do not drink 5 1/2 drinks per night out.) Ho: μDrinks
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Elements of a Test of Hypothesis 1. Null Hypothesis (H0 ) - A statement about the values of population parameters which we accept until proven false. 2. Alternative or Research Hypothesis (Ha )- A statement that contradicts the null hypothesis. It represents researcher’s claim about the population parameters. This will be accepted only when data provides sufficient evidence to establish its truth. 3. Test Statistic - A sample statistic (often a formula) that is used to decide whether to reject H0
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Ayomipo Burch Williams Loelius Strategic Management Concepts & Cases 07/22/2011 * Describe the key strategic challenges facing Apple Computer. * One of Apple biggest key issue will be the rate that technology is growing and the ability to keep up with and also the prices at which there products are sold for; they are face with constant new arrivals at prices that are more affordable especially in today’s economy where everybody is looking for ways to save money. They are
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SECURITY ANALYSIS AND PORTFOLIO MANAGEMENT | EFFICIENT MARKET HYPOTHESIS | | MRIGANKA DAS‚ 13/09 | INTRODUCTION: The Efficient Market Hypothesis and Random Walks One of the early applications of computers in economics in the 1950s was to analyze economic time series. Business cycle theorists believed tracing the evolution of several economic variables over time would clarify and predict the progress of the economy through boom and bust periods. A natural candidate for analysis
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1981‚ The relationship between return and market value of common stocks‚ Journal of Financial Economics 9‚ 3-18. Basu‚ Sanjoy‚ 1977‚ Investment performance of common stocks in relation to their price-earnings ratios: A test of the efficient market hypothesis‚ Journal of Finance 32‚ 663-682. Beebower‚ Gilbert L. and Gary L. Bergstrom‚ 1977‚ A performance analysis of pension and profit-sharing portfolios: 1966-75‚ Financial Analysts Journal 33‚ (May/June)‚ 31-42. Berkowitz‚ Stephen A.‚ Louis D. Finney
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The Efficient Market Hypothesis(EMH) was first given by Samuelson(1965)‚Fama(1965) and Mandelbrot(1966).It was based on “Random walk Theory”‚ and stated that since the market price will be affected by new information in the market‚ all available information have been fully reflected on the security price. There are three assumptions for the Efficient Market Hypothesis: 1.All investors are independent‚ rational‚ well-informed and hope for the highest profit; 2.All information are free and randomly
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