Question

Nine subjects were used in an experiment to determine if exposure to carbon monoxide has an impact on breathing capability. The data were collected by personnel in the Health and Physical Education Department at Virginia Tech and were analyzed in the Statistics Consulting Center at Hokie Land. The subjects were exposed to breathing chambers, one of which contained a high concentration of Co. Breathing frequency measures were made for each subject for each chamber. The subjects were exposed to the breathing chambers in random sequence. The data give the breathing frequency, in number of breaths taken per minute. Make a one-sided test of the hypothesis that mean breathing frequency is the same for the two environments. Use a = 0.05. Assume that breathing frequency is approximately normal. Subject With CO Without CO 30 30 2 45 3 26 25 4 25 23 5 34 30 51 49 7 46 41 32 35 9 30 28 6 8

Answer 1

This is a paired sample T test as the test subjects are the same in both the chambers

$H_0:\mu_D=0$

$H_a:\mu_D>0$

А E F H J K L 1 B With CO(X) 30 45 C Without CO (Y) 30 40 D difference (Y-X) o 5 2 3 4. 5 26 25 23 25 1 2 4 mean S.Dev AVERAGE(D2:010) STDEV.S(D2:010) 34 51 46 30 49 6 7 8 9 2.0000 2.5495 9 8 n= 2 5 -3 df 41 35 H7-1 32 30 28 2 10 11 2.3534 H5/(H6/SQRT(H7)) 12 13 14 15 16 17 18 19 Test statistic T = significance level = df One tailed P value = 0.05 8 0.0232 1-T.DIST.27(114,116) Conclusion: Reject the null hypothesis as the P value is <0.05 (significance level).

We have evidence that the breathing frequency is not the same for the two environments infact, breathing frequency is higher for environment with CO than without CO