A logging truck sales representative will phone either one or two potential buyers per day with probabilities of 0.25 and 0.75, respectively. Each contact will result in either no sale or a $75,000 sale with probabilities of 0.85 and 0.15, respectively. (Hint: start with a tree diagram)

a) Show the probability distribution of daily sales (in number of sales).

b) What is the expected value of daily sales (in dollars)?

c) What is the standard deviation of daily sales (in dollars)?