A rescue squad spokesperson claims that the squad receives an average of 3 calls per hour. If at most 6 calls were received over a 5-hour period, would you suspect that the spokesperson was overestimating the

Question

A rescue squad spokesperson claims that the squad receives an average of 3 calls per hour. If at most 6 calls were received over a 5-hour period, would you suspect that the spokesperson was overestimating the 
average number of calls received per hour? Explain based on the probability 
of this occurring.

If the expected number is 3/hr then in 5hrs there should be 5*3=15calls. It would not be real unusual to have 6 calls, the answer really depends on what the variance is, not just the average. If the variance is large this could be a perfectly acceptable number.