A bolt fabrication machine makes bolts with a target length of u = 15.125 millimeters. The machine has some variability, so the standard deviation of the length is o = 0.175 millimeter. The machine operator inspects a random sample of 12 bolts each hour for quality control
purposes and records the sample mean diameter, X. Assuming the process is working properly, what are the mean and standard deviation of
the sampling distribution of x