Reading 9: Common Probability Distributions LOS e题精选 2010, border, likely, following

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LOS e: Define a discrete uniform random variable and a binomial random variable.

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.

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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.

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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) 0.333.

B) 0.167.

C) 0.600.

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If the possible outcomes are X0,1,2,3,4,5), then the probability of each of the six outcomes is 1 / 6 = 0.167.