The registrar at a certain university has been asked to prepare a report about the graduate students. Among other things, she wants to analyze the ages of the students. She has taken a sample of 9 graduate students and the ages are shown below. Complete parts a and b.

27

25

22

26

27

28

26

23

21

a. Compute the range, interquartile range, and the standard deviation for these data.

The range is ?

Part 2

The interquartile range is ?

Part 3

The standard deviation is ?

Part 4

b. An earlier study showed that the mean age of graduate students in the same country as the university is 32.20

years. Based on your calculations in part a, what might you conclude about the age of students in that university?

A.

Since the mean age of students at the university is about 3 standard deviations above the national average, there appears to be evidence to suggest that the ages are higher at this university than for the nation's universities as a group.

B.

Since the mean age of students at the university is within 1 standard deviation of the national average, there appears to be evidence to suggest that the ages are different at this university than for the nation's universities as a group.

C.

Since the mean age of students at the university is about3standarddeviationsbelow the national average, there appearstobeevidence to suggest that the ages are lower at this university than for the nation's universities as a group.

D.

Since the mean age of students at the university is within1standarddeviationof the national average, there doesnotappeartobeevidence to suggest that the ages are different at this university than for the nation's universities as a group.