Suppose you plan to perform a two sample z-test (or log rank test) to compare the Covid-19 outcome between the vaccinated and unvaccinated groups.

What is the null hypothesis for this test in terms of the:

a.What is the null hypothesis for this test in terms of the incidence rate ratio(IRR) ?

b.What is thenull hypothesis for this test in terms of the survival curves for the randomization groups (S_vaccine(t) and S_placebo(t))?

c.Based on the resulting 95% confidence interval for the incidence rate ratio (or its compliment vaccine efficacy, given in the table), what can you ascertain about the p-value from the hypothesis test for items 32-22?