After taking many samples of size 4 of the length of a water pipe, was determined to be 0.973 meter. The process is in good statistical control and the individual length seem to follow the normal distribution.
(a) If 37.07% of the lengths are more than upper specification limit of .965+-.07 meter, find the process standard deviation.
(b) What percentage of lengths would fall outside the upper specification limit if the standard deviation was reduced to .0025 meter?