The probability that a cellular phone company kiosk sells X number of new phone contracts per day is shown below. x 4 5 6 8 10 P(x) 0.3 0.15 0.35 0.15 0.05 a) Find the mean, variance, and standard deviation for this probability distribution. b) Suppose the kiosk salesperson makes $80/day (8 hours at $10/hour), plus a $25 bonus for each new phone contract sold. What is the mean and variance of the salesperson's daily salary?