Question: The manufacturer of an airport baggage scanning machine claims it can handle an average of 530 bags per hour.

(a) At α = .05 in a left-tailed test, would a sample of 16 randomly chosen hours with a mean of 510 and a standard deviation of 50 indicate that the manufacturer’s claim is overstated?

(b) Why might the assumption of a normal population be doubtful? (See Aviation Week and Space Technology 162, no. 4 (January 24, 2005), p. 42.)