4) A product developer is interested in reducing the drying time of a primer paint. Two formulations of the paint are tested; formulation 1 is the standard chemistry, and formulation

2 has a new drying ingredient that should reduce the drying time. From experience, it is known that the standard deviation of drying time is eight minutes,and this inherent variability should be unaffected by the addition of the new ingredient. Ten specimens are painted with formulation 1 and another ten specimens are painted with formulation 2; the 20 specimens are painted in random order. The two-sample average drying times are X1=121 min and x2=112 min, respectively.What conclusions can the product developer draw about the effectiveness of the new ingredient, using a=0.05? Use the analysis of variance to test the hypothesis that different concentrations do not affect the mean tensile strength of the paper.