Basic Statistics

ANSWERS TO SELECTED PROBLEMS 237

Table B.1

Stem Leaf Stem Leaf

19 058 29

20 5 30

21 1 31

22 489 32

23 33

24 1199 34

25 0 113367 35

26 038 36

27 58 37

28 02347789 38

12 444

0 156

9

7

79

8

8

28

5

4.9 No answer.

Chapter 5

5.1 Age is ratio, gender is nominal, previous smoking status is nominal, length of

stay is ratio, and the four-point scale is ordinal.

5.2 (a) The mean is 136.98 and the standard deviation is 32.80. (b) The median is

128.5 and Q1 = 114 and 93 = 154.25. (c) No answer. (d) The mean is larger

than the median and the difference between Q1 and the median is 14.5, while

the difference between Q3 and the median is 25.75. The distribution appears

to be nonsymmetnc. (e) Check 87,93,212, and 230.

5.3 The mean is 14.0 and the standard deviation is 1.21.

5.4 The mean of all sample means is 3 and the mean of all sample variances would

be the population variance, or 2.

5.5 Use a statistical program to obtain the results.

Chapter 6

6.1 They will be simular.

6.2 Yes, the data appear to be symmetrically distributed and the distribution looks

normal. The simplest way to obtain the plots is to use a statistical program.

6.3 68.25% of the women.

6.4 Almost 100%.

6.5 15.87% of the women.

6.6 PSs = 172.9 pounds.