Need Help with this questions.

The Hoylake Rescue Squad receives an emergency call every 1, 2, 3, 4, 5, or 6 hours, according to the following probability distribution. The squad is on duty 24 hours per day, 7 days per week:

Time Between Emergency Calls (hr.) Probability

1 0.15

2 0.10

3 0.20

4 0.25

5 0.20

6 0.10

1.00

a. Simulate the emergency calls for 3 days (note that this will require a "running" , or cumulative, hourly clock), using the random number table.

b. Compute the average time between calls and compare this value with the expected value of the time between calls from the probability distribution. Why are the result different?