The true mean breaking strength of yarn used in manufacturing drapery material is required to be above 100 psi. From past data, the standard deviation of breaking strength is known to be 2 psi. Assume that the strength of yarn specimen follows normal distribution. Suppose the manufacturer decides to reject the null hypothesis whenever sample average of 9 specimens exceeds 100.9 psi.
Find the probability of Type II error if the true mean breaking strength is 101.5
Any help you can provide would be very much appreciated.