Consider the variable "AMprep" which is the amount of time, in minutes, it takes a student to get ready before his/her first class or meeting in the morning. Use the R output shown below to answer the following questions.

>

> fivenum(AMprep)

[1]915354773

>

> mean(AMprep)

[1] 35.23529

>

> sd(AMprep)

[1] 19.46320

(a) Calculate thez

z-score for the student who took theleastamount of time to get ready in the morning.

z

L

zL=

(b) Thez

z-score for the student who took themostamount of time to get ready in the morning isz=1.94031.

z=1.94031.

Based on thez

z-score of the student who used the least time and the student who used the most time, which student's prep time was more unusual compared to her/his peers?

?

Short AM prep time

Long prep time

Neither, the difference in times are the same

(c) Which of the following is the correct interpretation of the75

th

75thpercentile?

A.75

75% of the students spent fewer than47

47minutes on the morning preparations.

B.47

47students spent more time, on average, on morning prep.

C.75

75% of the students spent more than47

47minutes on morning preparations.

D.47

47students spent less time, on average, on morning prep.

Note:You can earn partial credit on this problem.