This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
A group tested for a drug shows 60% improvement as against a standard group showing 40% improvement. The best test to test the significance of result is- 
Select and explain. 
A. Student T test, B. Chi square test, C. Paired T test, D. Test for variance
B: Chi square test
Answer: B: Chi square test 
Explanation: Ref: Parks 23rd edition pg 852 Chi-square test offers an alternate method of testing the significance of difference between two propoions.Advantage: it can also be used when more than 2groups are to be compared. Ref:Parks 23rd edition pg 852 Tests of significance: Qualitative: Chi- square : 2 or more than 2 groups Mc Nemar test : 1 group. ( before and after intervention) Quantitative: Paired T test: 1 group Student T test/ unpaired T test: 2 groups Anova: more than 2 groups.