A computer sales store purchased 3 machines from a manufacturer. He will sell them for 1000 each. The manufacturer promised to buy back any unsold computers after 6 months for 200 each. For the store,...

A computer sales store purchased 3 machines from a manufacturer. He will sell them for 1000 each. The manufacturer promised to buy back any unsold computers after 6 months for 200 each. For the store, the acquisition cost of each machine is 600. Let X be the number of computers sold and their corresponding probabilities:

1. a) Calculate expected profit


2. b) Calculate the coefficient of variation.


3. c) It would be better to buy 2 machines instead of 3. Why?