A college reports that in the past, the ages of its undergraduate students was normally distributed with a mean of 21.3 years. In the following table, you are given ages that were obtained by taking a recent random sample of 9 undergraduate students.

age 19   22    23  19  21  22  19  23  21

a. Find the point estimate for the mean age of the undergraduate student population.

b. Find the point estimate for the standard deviation of the undergraduate student population.

c. Find the standard error of the sampling distribution.

d. Describe the sampling distribution of the mean for this sample of 9.

e. Find the margin of error for a 99% confidence level.

f. Find the interval estimate for the mean of the population at a 99% confidence level.

from:

to:

g. Write a sentence to interpret the result in part f.

h. Explain how and why the confidence interval would change if the confidence level was decreased to 95%.

i. Explain how and why the confidence interval would change if the sample size was increased.