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...

Extracted text: 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 65 clamps, the mean time to complete this step was 45.7 seconds. Assume that the population standard deviation is o - 8 seconds. Part 1 Construct an 80% confidence interval for the mean time needed to complete this step. Round to one decimal place, if necessary. An 80% confidence interval for the mean is [14.4 <17 part="" 2="" out="" of="" 2="" find="" the="" sample="" size="" needed="" so="" that="" a="" 90%="" confidence="" interval="" will="" have="" margin="" of="" error="" of="" 1.5.="" |is="" needed="" in="" order="" to="" obtain="" a="" 90%="" confidence="" interval="" with="" a="" margin="" a="" sample="" size="" of="" error="" of="">