Introductory Biostatistics

4.22 Group 95% Confidence Interval

Females ð 63 : 2 ; 152 : 0 Þ

Males ð 76 : 3 ; 119 : 3 Þ

4.23 x¼ 0 : 22

s¼ 0 : 66

SEðxÞ¼ 0 : 18

0 : 22 Gð 2 : 160 Þð 0 : 18 Þ¼ð
 0 : 16 ; 0 : 60 Þ

4.24 Group 95% Confidence Interval

Treatment ð 653 : 3 ; 676 : 9 Þ

Control ð 681 : 1 ; 722 : 7 Þ

4.25 (a)Mean:ð 0 : 63 ; 4 : 57 Þ;(b)correlation coe‰cient:ð 0 : 764 ; 0 : 981 Þ.

4.26 On log scale:ð 1 : 88 ; 2 : 84 Þ; in weeks:ð 6 : 53 ; 17 : 19 Þ.

4.27 Control: 7 : 9 Gð 1 : 96 Þð 3 : 7 Þ=

ffiffiffiffiffi

30

p

¼ð 6 : 58 ; 9 : 22 Þ

Simulation game: 10: 1 Gð 1 : 96 Þð 2 : 3 Þ=

ffiffiffiffiffi

33

p

¼ð 9 : 32 ; 10 : 88 Þ

4.28 (a) 25 : 0 Gð 1 : 96 Þð 2 : 7 Þ=

ffiffiffiffiffi

58

p

¼ð 24 : 31 ; 25 : 69 Þ;(b)on the average, people

with large body mass index are more likely to develop diabetes mellitus.

4.29 DBP Level Exposure 95% Confidence Interval

< 95 Yes ð 213 : 2 ; 226 : 8 Þ

No ð 216 : 0 ; 226 : 0 Þ

95–100 Yes ð 215 : 3 ; 238 : 6 Þ

No ð 223 : 6 ; 248 : 4 Þ

b 100 Yes ð 215 : 0 ; 251 : 0 Þ

No ð 186 : 2 ; 245 : 8 Þ

4.30 ð
0 : 220 ; 0 : 320 Þ.

4.31 ð 0 : 545 ; 0 : 907 Þ.

4.32 Standard:ð 0 : 760 ; 0 : 986 Þ, test:ð 0 : 820 ; 0 : 990 Þ.

4.33 With smoke:ð 0 : 398 ; 0 : 914 Þ, with sulfur dioxide:ð 0 : 555 ; 0 : 942 Þ.

4.34 Men:ð
0 : 171 ; 0 : 864 Þ, women:ð 0 : 161 ; 0 : 928 Þ.

4.35 AG positive:ð 0 : 341 ; 0 : 886 Þ, AG negative:ð
0 : 276 ; 0 : 666 Þ.

ANSWERS TO SELECTED EXERCISES 513