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 of clamps, the mean time to complete this step was seconds. Assume that the population standard deviation is seconds. Round the critical value to no less than three decimal places. Part: 0 / 2 0 of 2 Parts Complete Part 1 of 2 (a) Construct a confidence interval for the mean time needed to complete this step. Round the answer to at least one decimal place. A confidence interval for the mean is .