<prompt> Degree of freedom of a chi square test in contingency table of 2 by 2 is?1Zero24  <response>: - for a 22 contingency table two columns and two rows, the degree of freedom is 1. - d.f c-1 r-1 2-1 2-1 1 Reference : Parks textbook of preventive and social medicine, 23rd edition, pg no:852 