Listed in the accompanying data table are student evaluation ratings of courses and professors, where a rating of 5 is for "excellent." Assume that each sample is a simple random sample obtained from a population with a normal distribution.

a. Use the 93 course evaluations to construct a 95% confidence interval estimate of the standard deviation of the population from which the sample was obtained.

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(Round to two decimal places as needed.)

b. Repeat part (a) using the 93 professor evaluations. As in part (a), the requirements for constructing a confidence interval estimate of a population standard deviation are assumed to be satisfied, as indicated in the problem statement. Use technology to find the 95% confidence interval estimate of the population standard deviation for the professor evaluations, rounding to two decimal places.

c. Compare the results from part (a) and part (b).

Course Eval	Prof Eval
4.3	4.9
4.8	4.8
3.9	4
4.4	4.2
4.6	4.7
4.4	4.4
3.8	4.5
3.4	3.4
4.5	5.1
3.8	3.9
3.1	3.4
4.2	3.9
3.9	4.2
3.6	3.8
2.7	2.8
4.6	4.5
3.8	4.3
3.8	4.2
4	4.8
3.6	3.4
3.4	3.6
3.1	3.5
4	4.5
4.1	4.6
4.1	4.5
4.4	5
3.9	4.4
3.9	4.2
3.2	3.3
4.7	4.8
2.5	2.5
3.7	4.1
4.6	4.8
4.2	4.2
4	4.3
4.2	4
3.9	3.7
3.9	4.2
3.9	3.9
4.7	4.8
3.2	3.2
4.5	4.4
3.7	3.6
3.9	3.8
4.6	4.7
4.7	5.1
3.5	3.5
3.5	3.6
3.8	4.2
4.1	4.4
4.3	4.8
4.1	4.3
4.4	5.1
4	4.3
3.2	3.6
3.7	4.2
4.2	4
4.2	3.9
3.4	3.7
3.1	3
3.8	4.1
4.3	4.5
3.7	4
3.2	3.8
4.4	4.7
3.8	3.6
4.5	4.6
1.9	2.2
3.3	3
4.1	4.2
3.8	3.7
4.5	4.8
3.9	4
3.9	3.7
3.6	3.4
4.4	4.5
4.1	4.5
4.3	4
4.3	3.9
4.8	4.8
3.6	3.8
3.4	3.5
3.9	4.4
4.5	4.7
4.7	5.2
4.5	4.5
3.3	3.2
3.1	3.4
3.8	3.7
4.2	4
4	3.8
4.4	4.2
3.5	3.3