Amanufacturer claims that the average tensile strength of thread a is equal to the average tensile strength of thread b. to test this claim, 25 pieces of a type of thread and 36 pieces of b type of thread were tested under similar conditions. type a thread had an average tensile strength of 81 kilograms with a standard deviation of 5.2 kilograms, while type b thread had an average tensile strength of 76 kilograms with a standard deviation of 3.4 kilograms. test the manufacturer’s claim using a 0.05 level of significance.