Introduction to Probability and Statistics for Engineers and Scientists

420 Chapter 9: Regression

Number of Number of

Missing Rivets=x Alignment Errors=y

13 7

15 7

10 5

22 12

30 15

72

25 13

16 9

20 11

15 8

(d) Estimate the expected number of alignment errors of a plane having 24

missing rivets.

(e)Compute a 90 percent confidence interval estimate for the quantity in (d).

18.The following data give the average price of all books reviewed in the journal

Sciencein the years from 1990 to 1996.

Price (Dollars)

1990 1991 1992 1993 1994 1995 1996

54.43 54.08 57.58 51.21 59.96 60.52 62.13

Give an interval that, with 95 percent confidence, will contain the average price

of all books reviewed inSciencein 1997.

Problems 19 through 23 refer to the following data relating cigarette smoking

and death rates for 4 types of cancers in 14 states. The data are based in part on

records concerning 1960 cigarette tax receipts.

Cigarette Smoking and Cancer Death Rates

Deaths per Year per 100,000 People
Cigarettes Bladder Lung Kidney
State per Person Cancer Cancer Cancer Leukemia

California 2,860 4.46 22.07 2.66 7.06
Idaho 2,010 3.08 13.58 2.46 6.62
Illinois 2,791 4.75 22.80 2.95 7.27

(continued)