An experiment to compare the tension bond strength of polymer latex modified mortar (portland cement mortar to which polymer latex emulsions have been added during mixing) to that of unmodified mortar resulted in x = 18.14 kgf/cm2 for the modified mortar (m = 42) and y = 16.84 kgf/cm2 for the unmodified mortar (n = 32). let μ1 and μ2 be the true average tension bond strengths for the modified and unmodified mortars, respectively. assume that the bond strength distributions are both normal.