The weighted average of the possible values that a random variable X can assume, where the weights are the probabilities of occurrence of those values, is referred to as the:
A) variance.
B) standard deviation.
C) expected value.
D) covariance.

Question

The weighted average of the possible values that a random variable X can assume, where the weights are the probabilities of occurrence of those values, is referred to as the: 
A) variance.
B) standard deviation.
C) expected value.
D) covariance.

Quizplus · Accepted Answer

The definition provided in the question is that of the expected value, also known as the mean. The variance and standard deviation are measures of the spread or variability of the data, while covariance measures the degree to which two variables are related. None of these concepts are directly related to the weighted average of the possible values of a random variable. Therefore, the best choice is C, the expected value.

The Weighted Average of the Possible Values That a Random