The authors of the paper "Statistical Methods for Assessing Agreement Between Two Methods of Clinical Measurement"† compared two different instruments for measuring a person's ability to breathe out air. (This measurement is helpful in diagnosing various lung disorders.) The two instruments considered were a Wright peak flow meter and a mini-Wright peak flow meter. Seventeen people participated in the study, and for each person air flow was measured once using the Wright meter and once using the mini-Wright meter. mini

wright

meter wright meter

subject

1 512 494

2 430 395

3 520 516

4 428 434

5 500 476

6 600 557

7 364 413

8 380 442

9 658 650

10 445 433

11 432 417

12 626 656

13 260 267

14 477 478

15 259 178

16 350 423

17 451 427

(a)

Suppose that the Wright meter is considered to provide a better measure of air flow, but the mini-Wright meter is easier to transport and to use. If the two types of meters produce different readings but there is a strong relationship between the readings, it would be possible to use a reading from the mini-Wright meter to predict the reading that the larger Wright meter would have given. Use the given data to find an equation to predict y = Wright meter reading using a reading from the mini-Wright meter. (Round your values to three decimal places.)

y =

+

x

(b)

What would you predict for the Wright meter reading of a person whose mini-Wright meter reading was 563? (Round your answer to three decimal places.)

(c)

What would you predict for the Wright meter reading of a person whose mini-Wright meter reading was 342? (Round your answer to three decimal places.)