A machine is set produce tennis balls so the mean bounce is 36 inches ...

1. A machine is set produce tennis balls so the mean bounce is 36 inches when the ball is dropped from a platform of a certain height. The productions supervisor suspects that the mean bounce has changed and is less than 36 inches. As an experiment a sample of 12 balls was dropped from the platform and the mean height of the bounce was 35.5 inches, with a standard deviation of 0.9 inches. At the .05 significance level, can the supervisor conclude that the mean bounce height is less than 36 inches?