Introductory Biostatistics

3.22 (a)Right of 5.991: 0.05; right of 9.210: 0.01;(b)right of 6.348: between
0.01 and 0.05;(c)between 5.991 and 9.210: 0.04.

3.23 (a)Right of 3.32: 0.05; right of 5.39: 0.01;(b)right of 2.61:<0.01;(c)
between 3.32 and 5.39: 0.04.

3.24 k¼0.399, marginally good agreement.

3.25 k¼0.734, good agreement—almost excellent.

Chapter 4

4.1 m¼ 0 :5; 6 possible samples withmx¼ 0 : 5 ð¼mÞ.

4.2 Prðm
 1 axamþ 1 Þ¼Prð
 2 : 33 aza 2 : 33 Þ

¼ 0 : 9802

4.3 Group 95% Confidence Interval

Left-handed ð 0 : 444 ; 0 : 590 Þ

Right-handed ð 0 : 338 ; 0 : 384 Þ

4.4 Group 95% Confidence Interval

Students ð 0 : 320 ; 0 : 460 Þ

Workers ð 0 : 667 ; 0 : 873 Þ

4.5 Year 95% Confidence Interval

1983 ð 0 : 455 ; 0 : 493 Þ

1987 ð 0 : 355 ; 0 : 391 Þ

4.6 Level 95% Confidence Interval

High ð 0 : 402 ; 0 : 574 Þ

Low ð 0 : 077 ; 0 : 145 Þ

4.7 For whites: 25: 3 Gð 1 : 96 Þð 0 : 9 Þ¼ð 23 :54%; 27 :06%Þ

For blacks: 38: 6 Gð 1 : 96 Þð 1 : 8 Þ¼ð 35 :07%; 42 :13%Þ

No, sample sizes were already incorporated into standard errors.

4.8 Parameter 95% Confidence Interval

Sensitivity ð 0 : 575 ; 0 : 891 Þ

Specificity ð 0 : 964 ; 0 : 980 Þ

510 ANSWERS TO SELECTED EXERCISES