Part I. Chi-Square Goodness of Fit Test (equal frequencies)
Four different brands of a pain medication used for chronic back ailments were tested to see if the number of side effects for each brand were the same.
The table below lists the results of the reported number of side effects for each brand of pain medication.
|
Brand A
|
Brand B
|
Brand C
|
Brand D
|
|
23
|
17
|
33
|
11
|
[Hint: Be sure to watch the video at Week 5 Resourceson the "Chi-Square Goodness-of-Fit test (equal frequencies)" before
attempting this problem. Instructions for performing this test in STATDISK can be found in the Statdisk User Manual.]
1. Use the Chi-Square Goodness-of-Fit test to see if there is a difference between the number of side effects from the different brands of medication. Use a significance level of .01.
2. What are we trying to show here?
3. What is the p-value and what does it represent in the context of this problem?
4. State in your own words what the results of this Goodness-of-fit test tells us.
5. Repeat the above procedure using only Brands A, B, and D. Paste results here.
6. Do you get a different result?