7.

A researcher is interested in relating dose of a cough lozenge to clarity of speech among people suffering from a cold. Doses are varied along the range of X=0,2,4,6 mg. The following quantities are reported by research assistant (Y=clarity of speech measurement) based on a spreadsheet analysis of the data:

a)

Compute the estimate of increase in average clarity per unit increase in dose.

b)

Compute the correlation coefficient.

24. An accounting firm is ineterested in comparing their three interns in terms of the proportions of correctly completed tax forms. They sample 60 tax forms from each of the interns. Among Jack’s forms, 38 are correct, among Jill’s 45 are correct, and among Bob’s 37 are correct. Give the expected numbers of correct and incorrect forms for each intern, under the hypothesis that their true success rates are equal.

a) 30 correct & 30 incorrect

b) 120 correct & 60 incorrect

c) 60 correct & 60 incorrect

d) 90 correct & 90 incorrect

e) 40 correct & 20 incorrect

# The following 2 Problems are based on this information

A firm that prints flyers is interested in comparing the defective rates of 4 brands of copiers they are considering purchasing. They arrange to run 5000 copies on each of the 4 copiers, observing the numbers of defective and usable (non-defective) copies for each brand.

Brand \ Copy Quality

## Defective

## Non-defective

# Total

Canon

350

4650

5000

Konica

375

4625

5000

Sharp

425

4575

5000

Xerox

450

4550

5000

Total

1600

18400

20000

7.

Give the expected number of defective and non-defective copies for each brand under the hypothesis that the true defective rates are equal among the four brands.

a) Defective: 1200 Non-Defective: 18800

b) Defective: 2500 Non-Defective: 2500

c) Defective: 10000 Non:Defective: 100000

d) Defective: 300 Non-Defective: 4700