Lab Exercise for Chi-Square Test

1. Previously, we used INCPAD trial data to confirm that randomization is successful for a continuous patient characteristic variable ('age'). Now, we will revisit this trial data, but want to assess whether or not the randomization is still successful for a categorical characteristics variable ('gender'). The incpad2.sav data contains randomization assignment and one of the important demographic variable: gender. In the provided data, a variable named 'group' is used to define the randomization assignment; with '1' stands for intervention and '0' for control. Also, a variable named 'gender' is used with '1' indicated 'male, and '0' indicated 'female'. Again, we want to see if there is association between 'gender' by 'group' and make sure randomization works. Use the incpad2.sav data to complete the following:
2. Write the null hypothesis and the alternative hypothesis.

1. Report the four conditional probabilities.

(1) In intervention group, what percentage are male patients?

(2) In control group, what percentage are male patients?

(3) For those female patients, what percentage are assigned to intervention group?

(4) For those male patients, what percentage are assigned to intervention group?

1. Perform appropriate statistical test for part a. What is the test procedure you will chose?
2. What do you conclude? (report test statistics, include the degrees of freedoms and the corresponding p-value).
3. Can you confirm if our randomization successful (for 'gender' variable)?