标题: Reading 9: Common Probability Distributions LOS b习题精选 [打印本页]
作者: honeycfa 时间: 2010-4-15 22:41 标题: [2010]Session 3-Reading 9: Common Probability Distributions LOS b习题精选
LOS b: Describe the set of possible outcomes of a specified discrete random variable.
Assume a discrete distribution for the number of possible sunny days in Provo, Utah during the week of April 20 through April 26. For this discrete distribution, p(x) = 0 when x cannot occur, or p(x) > 0 if it can. Based on this information, what is the probability of it being sunny on 5 days and on 10 days during the week, respectively?
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A) |
A positive value; zero. | |
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B) |
A positive value; infinite. | |
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The probability of it being sunny on 5 days during the week has some positive value, but the probability of having sunshine 10 days within a week of 7 days is zero because this cannot occur.
作者: honeycfa 时间: 2010-4-15 22:41
Which of the following is least likely to be an example of a discrete random variable?
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A) |
The number of days of sunshine in the month of May 2006 in a particular city. | |
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B) |
The rate of return on a real estate investment. | |
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C) |
Quoted stock prices on the NASDAQ. | |
The rate of return on a real estate investment, or any other investment, is an example of a continuous random variable because the possible outcomes of rates of return are infinite (e.g., 10.0%, 10.01%, 10.001%, etc.). Both of the other choices are measurable (countable).
作者: honeycfa 时间: 2010-4-15 22:42
A random variable that has a countable number of possible values is called a:
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A) |
probability distribution. | |
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B) |
continuous random variable. | |
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C) |
discrete random variable. | |
A discrete random variable is one for which the number of possible outcomes are countable, and for each possible outcome, there is a measurable and positive probability. A continuous random variable is one for which the number of outcomes is not countable.
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