A Wendy's manager performed a study to determine a probability distribution for the number of people, X< waiting in line during lunch. The results were as follows:

Xp(X)X*p(X)

0......................................0.015

1......................................0.125

2......................................0.246

3......................................0.334

4......................................0.210

5......................................0.070

(a) Verify that this is a discrete probability distribution.

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

(c) Compute the standard deviation of the random variable X?

(d) What is the probability that 4 people are waiting in line for lunch?

(e) What is the probability that at least 4 people are waiting in line for lunch? Would this be unusual? Explain.