In a study of the effect of a medical treatment, a simple random sample of 300 of the 500 participating patients was assigned to the treatment group; the remaining patients formed the control group.
When the patients were assessed at the end of the study, favorable outcomes were observed in 162 patients in the treatment group and 97 patients in the control group.
Did the treatment have an effect, or is this just chance variation? Perform a statistical test, following the steps in Problems.

Question

In a study of the effect of a medical treatment, a simple random sample of 300 of the 500 participating patients was assigned to the treatment group; the remaining patients formed the control group. 
When the patients were assessed at the end of the study, favorable outcomes were observed in 162 patients in the treatment group and 97 patients in the control group. 
Did the treatment have an effect, or is this just chance variation? Perform a statistical test, following the steps in Problems.