Question: The length of time a domestic flight must wait between gate departure and takeoff taxi at BWI International Airport is approximately normally distributed with a mean of 22 minutes and a standard deviation of 7 minutes.

a. What is the probability that a plane must wait between 18 and 24 minutes before taxiing for

takeoff after leaving the gate?

b. What is the probability a plane must wait between 22 and 30 minutes before taxiing for takeoff

after leaving the gate?

c. What is the probability a plane waits more than 12 minutes between gate departure and takeoff

taxi?

d. What is the length of time such that only 5% of planes wait this long or longer before gate

departure and taxiing to the runway?