Efficient manufacturing:Efficiency experts study the processes used to manufacture items in order to make them as efficient as possible. One of the steps used to manufacture a metal clamp involves the drilling of three holes. In a sample of55

clamps, the mean time was59.1

seconds. Assume that the population standard deviation is= 12

seconds. Round the critical value to no less than three decimal places.

(b) Find the sample size needed so that a 98% confidence interval will have margin of error of 1.5 . A sample size of___ is needed in order to obtain a 98%confidence interval with a margin error of 1.5 . Round the sample size up to the nearest integer