In an effort to link cold environments with hypertension in humans, a preliminary experiment was conducted to investigate the effect of cold on hypertension in rats. Twelve rats were assigned at random to two groups (6 in a group), in which each group was exposed to a different environment. One group was held in a normal environment at 26C while the other group was held in a cold 5C environment. Blood pressures and heart rates were measured for rats in both groups. Note: group 1 = 5C and group 2 = 26C. Dataset: hypertension_2008.xls
a. Use the appropriate nonparametric test to determine if there is difference in blood pressure between the two temperature levels. State the null and alternative hypothesis, p-value (using the z-approximation) and conclusion within the context of the problem.
b. Using the exact method, what is the rejection region (i.e., critical values)? Does your conclusion change from the conclusion based on the approximate p-value?
c. What would be the consequence on the type I error of using a parametric test that does not meet the model assumptions?
This solution creates a null and alternative hypothesis and conducts a statistical analysis in Excel file. A decision rule is created and a two-tailed test is conducted to compare the z-statistic to the p-value to accept or reject the null hypothesis. A