An admissions director wants to estimate the mean age of all students enrolled at a college. The estimate must be within 1.3 years of the population mean. Assume the population of ages is normally distributed. (a) Determine the minimum sample size required to construct a 90% condence interval for the population mean. Assume the population standard deviation is 1 7 years. (b) The sample mean is 20 years of age. Using the minimum sample size wilt a 90% level of confidence, does it seem likely that the population mean could be within 9% of the sample mean? within 10% ofthe sample mean? Explain (a) The minimum sample size required to construct a 90% condence interval is I] students. (Round up to the nearest whole number.)