4 The number of sales that a telemarketing salesperson does

4. The number of sales that a telemarketing salesperson does in an hour is a random variable X

such that E(X) = 3:5 and V ar(X) = 1:25.

(a) The salesperson gets a base salary of $12 an hour plus a commission of $8 for every sale

he makes. Find the mean and standard deviation of Y , the total amount of money the

salesperson earns an hour.

(b) Find E(4X - X2 + :5)