statistics

The standard deviation of test scores on a certain achievement test is

11.5

. A random sample of

scores on this test had a mean of

72.9

. Based on this sample, find a

99%

confidence interval for the true mean of all scores. Then complete the table below.

Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.

(If necessary, consult a list of formulas.)

What is the lower limit of the

99%

confidence interval?

What is the upper limit of the

99%

confidence interval?