An aircraft strobe light is designed so that the times between flashes are normally distributed with a mean of 3.00 seconds and a standard deviation of 0.40 second.
a. What is the likelihood that an individual time is greater than 4.00 seconds?
b. What is the likelihood that the mean for 60 randomly selected times is greater than 4.00 seconds?
c. Given that the strobe light is intended to help other pilots see an aircraft, which result is more relevant for assessing the safety of the strobe light: the result in part a or the result in part b? Why?