(Solved): 4. To compute the variance of a discrete random variable, you need to know a. the variable's possi ...

4. To compute the variance of a discrete random variable, you need to know a. the variable's possible values. b. the expected value of the variable. c. the probability of each possible value of the variable. d. all of the above. 13. If \( P(A)=0.3, P(B)=0.2 \), and \( P(A \) and \( B)=0 \), what can be said about events \( A \) and \( B \) ? a. They are independent. b. They are mutually exclusive. c. They are posterior probabilities. d. None of the above.