with pretest experimental being 5,5,4,4,2 and post test experimental being 5,5,5,4,1 and pretest control being 5,5,3,2,1,and post test control being 5,5,3,2,1 Calculate the correlation coefficient (r) using the formula: r = [(xi - x)(yi - )] / sqrt[((xi - x)^2)((yi - )^2)]. Here, xi and yi are the individual pretest and posttest scores, and x and are the means of the pretest and posttest scores