The tensile strengths of two types of materials used in a company in the State of Washington were investigated by collecting 16 samples of each material (totally 32 samples). The sample mean for material 1 was 423.08 (psi), and for material 2 was 424.7 (psi). The sample standard deviation of the difference in tensile strengths was sD = 2.8 (psi). Is there sufficient evidence to conclude that two types of materials have the same tensile strength? Formulate and test the appropriate null H0 and alternative hypotheses H1 to verify the claim at level = 0.01