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Biostatistics

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REVIEW QUESTIONS AND EXERCISES 469<br />

X<br />

Methyl<br />

Mercury Intake<br />

ðmgHg=dayÞ<br />

Y<br />

Mercury in<br />

Whole Blood<br />

(ng/g)<br />

600 310<br />

550 290<br />

275 170<br />

580 375<br />

105 70<br />

250 105<br />

460 205<br />

650 480<br />

Find the regression equation describing the linear relationship between the two variables, compute r 2 ,<br />

and test H 0 : b 1 ¼ 0 by both the F and t tests.<br />

23. The following are the weights (kg) and blood glucose levels (mg/100 ml) of 16 apparently healthy<br />

adult males:<br />

Weight (X)<br />

Glucose (Y)<br />

64.0 108<br />

75.3 109<br />

73.0 104<br />

82.1 102<br />

76.2 105<br />

95.7 121<br />

59.4 79<br />

93.4 107<br />

82.1 101<br />

78.9 85<br />

76.7 99<br />

82.1 100<br />

83.9 108<br />

73.0 104<br />

64.4 102<br />

77.6 87<br />

Find the simple linear regression equation and test H 0 : b 1 ¼ 0 using both ANOVA and the t test. Test<br />

H 0 : r ¼ 0 and construct a 95 percent confidence interval for r. What is the predicted glucose level<br />

for a man who weighs 95 kg? Construct the 95 percent prediction interval for his weight. Let a ¼ :05<br />

for all tests.<br />

24. The following are the ages (years) and systolic blood pressures of 20 apparently healthy adults:<br />

Age (X) BP(Y) Age (X) BP(Y)<br />

20 120 46 128<br />

43 128 53 136<br />

63 141 70 146<br />

(Continued )

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