How do I set up to answer at least the first three parts comparing the null to the RR, RD, and OR for this question below (21-23)

There were 821 subjects enrolled in this study. Of the 414 randomized to the treatment (Hydroxychloroquine) arm, 49 (11.8%) developed Covid (or probable Covid) within 14 days of randomization. Of the 407 randomized to the placebo arm, 58 (14.3%) developed Covid (or probable Covid) within 14 days of randomization. In Homework #3, you reported a sample relative risk of treatment failure for the DAJ group compared to the EMS group of 0.83 with a 95% CI of 0.58 to 1.19.

Suppose you plan to perform a chi-square (or two sample z-test, or Fisher's Exact Test) for this study. What is the null hypothesis for this test in terms of the:

21. Risk difference (RD)

22. Relative risk (RR)

23. Odds ratio (OR)