A machine produces parts with lengths that are normally distributed with=0.57. A sample of11parts has a mean length of75.

(a) Give a point estimate for. (Give your answer correct to two decimal places.)

(b) Find the90%confidence maximum error of estimate for. (Give your answer correct to three decimal places.)

(c) Find the90%confidence interval for. (Give your answer correct to three decimal places.)Lower Limit

Upper Limit