Read the two statements and choose the correct option. I. Var(X) = E(X^2) - [E(X)]^2. II. The variance of a random variable can be negative when its mean is negative.

Random Variables, Expectation & Variance · Question 60 of 68

Question 60

MediumOriginal question

Read the two statements and choose the correct option.
I. $\text{Var}(X) = E(X^{2}) - [E(X)]^{2}$ .
II. The variance of a random variable can be negative when its mean is negative.

Only ICorrect answerYour answerOnly IICorrect answerYour answerBoth I and IICorrect answerYour answerNeither I nor IICorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

I is the short formula for the variance. True.
II: variance is an average of squared deviations, so it is never negative, whatever the mean. False.

Ten questions from Random Variables, Expectation & Variance, at your own pace.

Ten questions from Random Variables, Expectation & Variance, at your own pace.