Question

4. Electrodeposition process coats a rare metal on an instrument panel component to resist corrosion in the field. After the deposition process the parts are dried at two temperatures to harden the deposition. The hardness of the deposited metal is sampled at two temperatures randomly and the results are shown below in hardness units. 1000F temp: 8.097, 7.089, 11.176, 11.739, 8.315, 6.467, 10.759, 11,291 1200F temp: 8.963, 3.772, 7.418, 8.133, 7.015, 7.461, 6.748, 5.263 Is there any evidence to support the claim that the higher drying temperature gives a lower mean hardness? The variances for the two temperatures are 4.41 (1000F) and 2.54 (1200F)
4.1 What is the null hypothesis?
4.2 What is the alternative hypothesis?
4.3 What is the value of Sp?

4.4 What is the t statistic using α = 0.05

4.5 The conclusion is:

Answer 1

There is enough evidence to support the claim that the higher drying temperature gives a lower mean hardness.