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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Modelling 2 Week 3: Discrete Random Variables Stephen Bush Department of Mathematical Sciences MM2: Statistics - Week 3 - 1 Random Variables • Reference: Devore § 3.1 – 3.5 • Definitions: • An experiment is any process of obtaining one outcome where the outcome is uncertain. • A random variable is a numerical variable whose value can change from one replicate of the experiment to another. • Sample means and sample standard deviations are random variables • They are different
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Random Acts of Kindness For our Random act of Kindness project we decided to surprise a teacher with flowers‚ candy‚ and pictures of her favorite animals. We chose Mrs. Adams because we all like her as a teacher and she was recently going through a hard time. I brought her some flowers‚ purchased some of favorite candy‚ and drew pictures of her favorite animals. During advisory we placed the gifts right by her door and knocked on her door. We then ran away and left the gifts as a surprise. Who
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Selected Answer: .5006 . Question 5 .5 out of 5 points An automotive center keeps tracks of customer complaints received each week. The probability distribution for complaints can be represented as a table or a graph‚ both shown below. The random variable xi represents the number of complaints‚ and p(xi) is the probability of receiving xi complaints. xi 0 1 2 3 4 5 6 p(xi) .15 .1 .28 .20 .10 .10 .07 What is the expected number of complaints received per week? Round
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provide the required estimates with associated margins of uncertainity‚ arising from examining only a part and not the whole. Methods of Sample Selection Simple Random Sampling In this method each item of the data ( population) has the same probability of being selected in the sample. The selection is usually made with the help of random numbers. * Suppose there are N=850 students in a school from which a sample of n=10 students is to be taken. The students are numbered from 1 to 850. Since our
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What are Random Essay Topics? The meaning of random essay topics is in the word itself. To be put into a crux‚ the word random means any. Here‚ it means the topics can be from any subject. There are no specifications that the topic should be from a particular subject or should be of a particular genre. The topic can be on anything and in any form. The writer is not given rules that need to be followed while writing. The writers are given full freedom; they can even adapt or use the essay topics
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continuous random variable because the time is being measured. All possible results for the variable time (t) would be greater than > 0. b) The weight of a T-bone steak is a continuous random variable because the weight of the steak is measured. All the possible results for the weight of the T-bone steak would be positive numbers making the variable weight (w) > greater than 0. c) The number of free throw attempts before the first shot is made is a discrete random variable
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Depending on how a sample is drawn‚ it may be a random sample or a nonrandom sample. A random sample is a sample drawn in such a way that each member of the population has some chance of being selected in the sample. In a nonrandom sample‚ some members of the population may not have any chance of being selected in the sample. Suppose we have a list of 100 students and we want to select 10 of them. If we write the names of all 100 students on pieces of paper‚ put them in a hat‚ mix them‚ and then
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Kindle Versus Nook College students face many challenges; they have to make sure their classwork is done well‚ and completed in a timely fashion. Many have to find a way to balance school and a career as well as making sure that family obligations and scholastic responsibilities are both met. With all that to deal with the last thing most students want to worry about is carrying around books. Thankfully modern technology has addressed this issue with the E-Reader. An E-Reader will allow people to
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There are many ways to select a random sample. Four of them are discussed below: Simple Random Sampling: In this sampling technique‚ each sample of the same size has the same probability of being selected. Such a sample is called a simple random sample. One way to select a simple random sample is by a lottery or drawing. For example‚ if we need to select 5 students from a class of 50‚ we write each of the 50 names on a separate piece of paper. Then‚ we place all 50 names in a hat and mix them thoroughly
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