The quarterly sales levels (in millions of dollars) of two U.S. retail giants are dependent on the general state of the national economy in the coming months. The file P04_23.xlsx provides the...

The quarterly sales levels (in millions of dollars) of two U.S. retail giants are dependent on the general state of the national economy in the coming months. The file P04_23.xlsx provides the probability distribution for the projected sales volume of each of these two retailers in the next quarter. a. Find the mean and standard deviation of the quarterly sales volume for each of these two retailers. Compare these two sets of summary measures. b. Find the covariance and correlation for the given quarterly sales volumes. Interpret your results.