EXERCISE STUDY. Data on 40 subjects.

File names beginning with EXERCISE contain these data.

The pulse of each of 40 persons was taken, before and after running

one mile.

N of Cases: 40

Total # of Defined Variable Elements: 7

Variable Information:

Name Position

ID * No label * 1

SEX * No label * 2

Value Label

1 MALE

2 FEMALE

SMOKE * No label * 3

Value Label

0 NO

1 YES

AGE * No label * 4

PULSE_1 PRE-EXERCISE PULSE RATE 5

PULSE_2 POST-EXERCISE PULSE RATE 6

NAME * No label * 7

Using the EXERCISE data set, new variable PUL GAIN which is the difference in the post-exercise ( PULSE 2) and pre-exercise pulse ( PULSE 1) rates and compare the variability of smokers and non smokers on this variable.

(a) Specify the appropriate null and alternative hypotheses for this question.

(b) Use SAS to perform a test of the hypotheses from part a using significance level = 0.05.

(c) Explain the result of the hypothesis test from part b in terms of the language of the original problem.

(d) Set the 90% CI for the ratio of the variances.