答案和详解如下： Q1. Which of the following random variables would be most likely to follow a discrete uniform distribution? A) The outcome of a roll of a standard, six-sided die where X equals the number facing up on the die. B) The number of heads on the flip of two coins. C) The outcome of the roll of two standard, six-sided dice where X is the sum of the numbers facing up. Correct answer is A) The discrete uniform distribution is characterized by an equal probability for each outcome. A single die roll is an often-used example of a uniform distribution. In combining two random variables, such as coin flip or die roll outcomes, the sum will not be uniformly distributed. Q2. The number of days a particular stock increases in a given five-day period is uniformly distributed between zero and five inclusive. In a given five-day trading week, what is the probability that the stock will increase exactly three days? A) 0.167. B) 0.333. C) 0.600. Correct answer is A) If the possible outcomes are X 0,1,2,3,4,5), then the probability of each of the six outcomes is 1 / 6 = 0.167. | 
发表于 2009-1-9 10:19
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