An airline executive wishes to know if her airline is on schedule. She collects data on the deviations from actual takeoff time. From a random sample of 35 takeoff deviations she finds the mean to be 4.59 minutes (positive deviations being late) with a standard deviation of 16.32 minutes.
a. Is there sufficient evidence to conclude that the mean airline take off deviation is not zero at the 0.05 level of significance?
b. Suppose the executive took a sample of 100 take off deviations and found the same sample mean and standard deviation. What would her conclusion be then?