Mean Grade Point Average. As part of a study of grade inflation, you want to estimate the mean GPA of all current college student in the U.S. All GPAS are to be standardized for a scale between 0 and 4. how many GPA averages must be obtained so that the sample mean is within 0.2 of the popluation mean? Assume that a 99% confidence level is desired. Also assume that a pilot study showed that the population SD is estimated to be 0.79. Does it make sense to collect the entire sample at your college?