The goal at U.S. airports handling international flights is to clear these flights within 45 minutes. Let’s interpret this to mean that 95% of the flights are cleared in 45 minutes, so 5% of the flights take longer to clear. Let’s also assume that the distribution is approximately normal.

a. If the standard deviation of the time to clear an international flight is 5 minutes, what is the mean time to clear a flight?

b. Suppose the standard deviation is 10 minutes, not the 5 minutes suggested in part (a).

What is the new mean?

c. A customer has 30 minutes from the time her flight lands to catch her limousine. Assuming a standard deviation of 10 minutes, what is the likelihood that she will be cleared in time?