Section S.4 – Solutions to the Practice Problems

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1.

a. $2.00
b. $7.81
c. $0.64

2.

a. 14.2
b. 20.81 sec
c. 4.07 sec

3.

a. $338.40/credit hour
b. $316.04/credit hour

4.

a.

Enrollment	Frequency
0 – 5999	16
6000 – 11999	12
12000 – 17999	3
18000 – 23999	2
24000 – 29999	2

b.

c. 8628.7
d. 6943.9

5.

a.

Age	Frequency
21-24	6
25-28	3
29-32	4
33-36	8
37-40	4
	n = 25

b.

c. 30.68 years
d. 6.09 years

6.

a. 1.48
b. 1.12
c. 0, 1 , 1, 2 , 4

d.

7.

• a. 1, 3, 4, 5, 7

b.

8.

• a. $87, $175, $218, $416, $1300

b.

c. $175 is the 25^th percentile
d. $218 is the 50^th percentile

9.

a. 236.3 lbs.
b. 37.9 lbs.
c. 174, 206, 241, 272, 302

d.

10.

• a. 3, 4 , 4, 6 , 7

b.

c. The 50^th percentile is 4
d. The 75^th percentile is 6

11.

a. 30, 40, 75, 90, 99
b. 40, 75, 90, 94, 105
c. Kendra makes more money, $50 thousand more

12. 75%

13.

a. 7-series
b. 3-series
c. No, the age increases with each series and people tend to make more money as they get older.

14.

15.

a. 50
b. 25
c. 1178
d. 1767

16.

a. 15
b. 57
c. 836
d. 1292

17.

a. 25
b. 50
c. 50
d. 75

18.

a. Male Artists. All of the data items for men are greater than the greatest data item for the women.
b. Male Artists 93, Female Artists 58
c. Male Artists. There is a greater spread in the data for the men.
d. Male Artists 32.64, Female Artists 6.82

19. The Arnold Family, their standard deviation is higher, which means that their bills vary more.

20. Richard Mulligan, his standard deviation is lower, which means he is more consistent.

21.

a. 25
b. 8.72
c. 25, 27.5, 35, 40, 50

22.

a. 7
b. 2.20
c. 1, 2, 5, 6, 8