Question: A machine is set to produce tennis balls so the mean bounce is 36 inches when the ball is dropped from a platform of a certain height. The supervisor suspects that the mean bounce has changed and is less than 36 inches. As an experiment 42 balls were dropped from the platform and the mean height of the bounce was 35.5 inches, with standard deviation of 0.9 inches. At the 0.05 significance level, can the supervisor conclude that the mean bounce height is less than 36 inches?