25.11.2014 Views

Biostatistics

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

468 CHAPTER 9 SIMPLE LINEAR REGRESSION AND CORRELATION<br />

Y<br />

PBV (ml/sqM)<br />

X<br />

PBF (L/min/sqM)<br />

233 3.51<br />

370 4.24<br />

531 19.41<br />

516 16.61<br />

211 7.21<br />

439 11.60<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 test and the t test. Let a ¼ :05.<br />

21. Fifteen specimens of human sera were tested comparatively for tuberculin antibody by two methods.<br />

The logarithms of the titers obtained by the two methods were as follows:<br />

Method<br />

A (X)<br />

B (Y)<br />

3.31 4.09<br />

2.41 3.84<br />

2.72 3.65<br />

2.41 3.20<br />

2.11 2.97<br />

2.11 3.22<br />

3.01 3.96<br />

2.13 2.76<br />

2.41 3.42<br />

2.10 3.38<br />

2.41 3.28<br />

2.09 2.93<br />

3.00 3.54<br />

2.08 3.14<br />

2.11 2.76<br />

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

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

22. The following table shows the methyl mercury intake and whole blood mercury values in 12 subjects<br />

exposed to methyl mercury through consumption of contaminated fish:<br />

X<br />

Methyl<br />

Mercury Intake<br />

ðmgHg=dayÞ<br />

Y<br />

Mercury in<br />

whole blood<br />

(ng/g)<br />

180 90<br />

200 120<br />

230 125<br />

410 290<br />

(Continued )

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!