The following summary data on bending strength (lb-in/in) of joints is taken from the article Bending Strength of Corner Joints Constructed with Injection Molded Splines (Forest Products J., April, 1997: 8992). Assume normality for both populations. Type Sample Size Sample Mean Sample Standard Deviation

Without side coating 10 80.95 9.59

With side coating 10 63.23 3.96 a. State the hypotheses of interest, and perform an appropriate test at signicance level = 0.1 forthestatementthatthereisdifferenceinthevarianceofthestrengthsfor the two types of joints. b. Assume Normality for both populations. State the hypotheses of interest, and perform an appropriate test at signicance level = 0.05 for the statement that there is difference in the average strengths for the two types of joints