Question

Caffeine is a stimulant widely used by the general human population and may have an effect on oxygenation within the bloodstream. You are tasked with evaluating coffee consumption (due to its high caffeine content) to see if there is an effect of caffeine on the oxygen partial pressure (P_O2) of blood in normal subjects. In the first group, the subjects are placed on a no coffee diet, while the second group of subjects have at least 2 cups of coffee every day. After 1 week, the P_O2 level for each subject is measured in each group. Determine if there is a significant difference in P_O2 level between the two coffee groups of subjects.

PO2 for Two Groups of Treatment
Group 1 - No coffee (mmHg)	Group 2 - At least 2 cups of coffee every day (mmHg)
79	63
83	71
68	46
59	57
81	53
76	46
80	57
74	76
58	52
49	68
68	73

In this exercise, you have the information necessary to complete the five step process for statistical hypotheses testing to determine the effect of caffeine (via coffee). For your answer, include the following:

• State the null hypothesis and the alternative hypothesis based on your research question.
• Set the alpha level of 0.05 (5% chances in making a type I error. Calculate the value of the appropriate statistic (T)). Indicate the degrees of freedom for the statistical test.
• Write the decision rule for rejecting the null hypothesis based on finding the critical T-value from the T-Table.
• Write a summary statement based on the decision (significant or not, and why?)
  

Answer 1

Decision :

There is sufficient evidence to conclude that there is significant difference in po2 level between the two coffee groups of subjects.