You want to estimate the mean amount of annual tuition
You want to estimate the mean amount of annual tuition being paid by current full-time college students in the United States. First use the range rule of thumb to make a rough estimate of the standard deviation of the amounts spent. It is reasonable to assume that tuition amounts range from $0 to about $45,000. Then use that estimated standard deviation to determine the sample size corresponding to 99% confidence and a $100 margin of error. Does the resulting sample size seem practical? Find the sample size required to estimate the population mean.

You want to estimate the mean amount of annual tuition