PLS HELP


Assume that all grade-point averages are to be standardized on a scale between 0 and 5. How many grade-point averages must be obtained so that the sample mean is within 0.009 of the population mean? Assume that a 98% confidence level is desired. If using the range rule of thumb, o can be estimated as
Range/4 = 5-0/4 = 1.25. Does the sample size seem practical?