6. A process is to produce a product that will stand an average force of 20,000 pounds.

The variance of the product’s strength is 727,618 pounds-squared.

a. Specify the control limits for _X so that a = 0.05 when samples of size 4 are used.

b. Establish control limits for X when samples of size 5 are to be taken and the desired probability of a type I error is 0.03.