5.56. What is the purpose of forming a confidence interval for a parameter? What can you learn from it that you could not learn from a point estimate of the parameter?

5.57. An interval estimate for a mean is more informative than a point estimate, because with an interval estimate you can figure out the point estimate, but with the point estimate alone you have no idea how wide the interval estimate is.

(a) Explain why this statementis correct, illustrating using the reported 95% confidence interval of (4.0, 5.6) for the mean number of dates in the previous month for women at a particular college.

(b) The confidence interval in

(a) used a sample size of 50. What were the sample mean and standard deviation?