An admissions director wants to estimate the mean age of all students enrolled at a college. The estimate must be within 1.2 years of the population mean. Assume the population of ages is normally distributed.

(a) Determine the minimum sample size required to construct a 90% confidence interval for the population mean. Assume the population standard deviation is 1.8 years.

(b) The sample mean is 20 years of age. Using the minimum sample size with a 90% level ofconfidence, does it seem likely that the population mean could be within 8% of the samplemean? within 9% of the samplemean? Explain.

(a) The minimum sample size required to construct a 90% confidence interval is

The answer is 7 students.

pls fill in the blanks in the parenthesis.

(b) The 90% confidence interval is ( ),( ), It ( )(does not or does) seem likely that the population mean could be within 8% of the sample mean because 8% off from the sample mean would fall ( )(outside or inside) the confidence interval. It ( ) (does not or does) seem likely that the population mean could be within 9% of the sample mean because 9% off from the sample mean would fall ( ) (inside or outside) the confidence interval.