Question

The following experiments were conducted. State the null and alternative hypothesis and identify which analysis (e.g., one-sample t-test) the experimenter should use to analyze the data.

Dr. Nordeng is interested in response to stress in cats following removal from their mother. Ten litters of 3 kittens were used. One kitten was removed from its mother at 6 weeks, one at 8 weeks, and the other 10 weeks after birth. A blood test at 20 weeks of age provided the data: amount of cortisol in the blood. He assumes the cortisol levels in kittens are normally distributed and that the various populations have homogeneous variances.

Answer 1

Null Hypothesis H0: Mean cortisol levels in kittens of all three groups are equal.

Alternative Hypothesis Ha: At least one of the groups have different mean cortisol levels.

Since, we need to test the equality of mean cortisol levels of more than two groups, we would use one-way Anova test.

Also, the assumptions of Anova test are satisfied.

1. The cortisol levels in kittens are normally distributed

2. Various populations have homogeneous variances.

Thus, we would use one-way Anova test for the hypothesis test.