A researcher wants to estimate the mean grade point average of all current college students in the United States. She has developed a procedure to standardize scores from colleges using
something other than a scale between 0 and 4. How many grade point averages must be
obtained so that the sample mean is within 0.1 of the population mean? Assume that a 90%
confidence level is desired. Also assume that a pilot study showed that the population standard
deviation is 0.88.