A travelling salesman makes a sale on 65% of his calls on regular customers. He makes four sales calls ...

A travelling salesman makes a sale on 65% of his calls on regular customers. He makes four sales calls each day. Construct the probability distribution of X, the number of sales made each day. Find the probability that, on a randomly selected day, the salesman will make a sale. Assuming that the salesman makes 20 sales calls per week, find the mean and standard deviation of the number of sales made per week.