Infected with COVIDNot Infected with COVIDVaccine group419,983Placebo group13925,090

The table above shows the result of a clinical trial for COVID vaccine at a point in time before the study ended.

The researcher wants to test the preliminary result for association between which groups the volunteers were assigned and their infection status. Explain whether it is valid to perform a chi-square test.

Infected with covlo Not Infected with covlo Placebo group 139 25,0?0 The table above shows the result of a clinical trial for CDVID vaccine at a point in time before the studv ended. The researcher wants to test the preliminary result for association between which groups the volunteers were assigned and their infection status. Explain whether it is valid to perform a chi- square test