Chi-squared: A study is designed to investigate whether there is a difference in response to various treatments in patients with rheumatoid arthritis. The outcome is patient's self-reported effect of treatment into 1 of 3 categories. The data are shown below. Is there a significant difference in effect of treatment? Run the test at a 5% level of significance. What is the expected value for those people in treatment 1 whose symptoms worsened? Accept or Reject the H0?
|
Symptoms Worsened
|
No Effect
|
Symptoms Improved
|
Total
|
|
Treatment 1
|
22
|
14
|
14
|
50
|
|
Treatment 2
|
14
|
15
|
21
|
50
|
|
Treatment 3
|
9
|
12
|
29
|
50
|
|
Total
|
45
|
41
|
64
|
150
|