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.

Use the 93 course evaluations to construct a 98% confidence interval estimate of the standard deviation of the population from which the sample was obtained. Repeat part (a) using the 93 professor evaluations. Compare the results from part (a) and part (b).

a. __ < σ <  ___

b. __ < σ < ___

c. Compare the results. Choose the correct answer below.

A. The intervals overlap, so the populations appear to have amounts of variation that are substantially different.

B.The intervals overlap, so the populations appear to have amounts of variation that are not substantially different.

C.The intervals do not overlap, so the populations appear to have amounts of variation that are substantially different. The course evaluations have a significantly larger population standard deviation than the professor evaluations.

D.The intervals do not overlap, so the populations appear to have amounts of variation that are substantially different. The professor evaluations have a significantly larger population standard deviation than the course evaluations.

E.The results cannot be directly compared.

F.The intervals do not overlap, so the populations appear to have amounts of variation that are not substantially different.

Course Eval    Prof Eval
4.0                       4.9
4.6                       4.7
4.0                       3.9
4.1                       4.7
4.2                       4.8
4.1                       4.4
4.2                       4.4
3.5                       3.4
5.0                       4.6
3.9                       4.2
3.4                       3.8
3.7                       4.0
3.6                       3.9
3.5                       3.7
2.9                       2.7
4.3                       4.5
4.2                       4.4
3.6                       3.8
4.3                       4.8
3.7                       3.3
3.7                       3.7
3.5                       3.6
4.2                       4.1
4.6                       4.6
4.3                       4.6
4.4                       4.8
4.0                       4.6
3.7                       4.7
3.4                       3.5
4.2                       4.4
2.3                       2.2
3.5                       4.2
4.5                       4.7
3.6                       3.9
3.9                       4.1
4.0                       4.4
4.0                       3.7
3.9                       3.9
3.8                       3.9
4.5                       4.5
3.8                       3.4
4.6                       4.3
3.1                       3.3
3.6                       4.1
4.7                       4.6
4.8                       5.0
3.3                       3.4
3.8                       4.0
4.1                       4.6
3.8                       4.4
4.2                       4.6
4.1                   4.0
4.5    4.9
3.6    4.4
3.0    3.3
3.8    3.8
3.6    3.7
3.9    4.3
3.3    3.8
3.0    3.5
3.8    4.2
4.3    4.8
3.5    3.5
3.3    3.5
4.0    4.6
3.4    3.8
4.0    4.3
2.2    2.6
3.1    2.8
4.4    4.5
3.5    3.8
4.7    5.1
3.7    4.4
3.6    3.9
3.9    3.9
4.7    4.7
4.2    4.5
4.6    4.1
4.3    3.7
4.9    5.0
3.6    3.3
3.5    3.3
4.0    4.2
4.9    4.6
4.9    4.6
4.3    4.4
3.6    3.0
3.3    3.5
3.8    3.7
3.8    3.9
3.8    3.6
4.5    4.8
3.1    3.4