Suppose X and Y are independent random variables. The variance of X is equal to 16; and the variance of Y is equal to 9. Let Z = X - Y. What is the standard deviation of Z?

A card is drawn randomly from a deck of ordinary playing cards. You win $10 if the card is a spade or an ace. What is the probability that you will win money from playing the game once?

Which of the following is NOT essential for multiple regression modeling?

What is the cumulative probability at -1 standard deviation for a normal distribution?

Suppose E and F are independent events in a sample space S. Suppose further that E has probability .3 and F has probability .4. What is the probability of the union of E and F?

Suppose E and F are events in a sample space S. Suppose further that E has probability .5, F has probability .6, and the intersection of E and F has probability .2. Find the probability of the union of E and (the complement of F).

Symbolism: What does the Greek letter mu represent (without any other symbols) in statistics?

C(n,r) is equal to...

Which of the following is a characteristic of an F-distribution?

A manager of a large bank wants to compute the average interest rates across all bonds that the bank invests in. The manager randomly sampled 127 bonds that the bank invests in and calculated the average interest rate over the past year of the sample was 2.47%. What is the parameter of interest in this study?

A bag contains 4 balls (2 red and 2 blue). You pull out one ball at a time without replacement. What is the probability that the fourth ball chosen is a red ball?