A notebook computer dealer mounts a new promotional campaign. Purchasers of new computersmay, if dissatisfied for anyreason, return them within 2 days of purchase and receive a full refund. The cost to the dealer of such a refund is $100. The dealer estimates that 12% of all purchaserswill, indeed, return computers and obtain refunds. Suppose that 50 computers are purchased during the campaign period. Complete parts a. and b. below.

a. Find the mean and the standard deviation of the number of these computers that will be returned for refunds.

Themean, , is

.

(Round to one decimal place asneeded.)

The standarddeviation, , is

.

(Round to one decimal place asneeded.)

b. Find the mean and standard deviation of the total refund cost that will accrue as a result of these 50 purchases.

Themean, , is $

.

(Round to two decimal places asneeded.)

The standarddeviation, , is $

.

(Round to two decimal places asneeded.)