The Stanley Cup is a best-of-seven series to determine the champion of the National Hockey League. The following data represent the number of games played, X, in the Stanley Cup before a champion was determined from 1939 to 2015.

x Frequency

4...........................20

5...........................18

6...........................22

7...........................16

(a) Construct a probability model for the random variable X, the number of games in the Stanley Cup.

(b) Graph the discrete probability distribution.

(c) Compute and interpret the mean of the random variable X.

(d) Compute the standard deviation of the random variable X.