According to international standards, a tennis ball should have an internal pressure of 14 psi. Wilson claims that the pressure in tennis balls they make follow a normal distribution with a population mean of 14 and a population standard deviation of 2. A quality control expert has taken a sample of 9 balls to test the variability in the pressure. Let X1, X2, . . . , X9 be the balls and let S² be the same variance.
(a) What is the distribution of 8S²/4? Give the name as well as the parameters of the distribution.
(b) Find P(S² > 0.8232).