Question

1. Myocardial blood flow (MBF) was measured for two groups of subjects after five minutes of bicycle exercise. The normoxia (“normal oxygen”) group was provided normal air to breathe whereas the hypoxia group was provided with a gas mixture with reduced oxygen to simulate high altitude. The results (ml/min/g) are shown in the table below.

	NORMOXIA X	HYPOXIA Y
	3.45	6.37
	3.09	5.69
	3.09	5.58
	2.65	5.27
	2.49	5.11
	2.33	4.88
	2.28	4.68
	2.24	3.50
	2.17
	1.34
n	10	8
Sample mean	2.51	5.14
Sample sd	0.60	0.84

We wish to investigate the effect of hypoxia on MBF.

1. Construct a 90% confidence interval for the differences of the mean MBF for the two groups, i.e. .
2. Use the above confidence interval to conduct a hypothesis test with .

Answer 1

(a)

(b)

Since confidence interval does not contain zero so we can conclude that there is a significant difference between  the mean MBF for the two groups.

That is hypoxia has an effect on MBF.