題組內容

3. (20 points)In an accelerated life test, the principal material is aged by exposing it to 70°C for 168 hours. The tensile strength of the specimens of this material is measured before and after the aging process. The following data (in psi) are recorded:
66e7dd128e502.jpg Find a 99% confidence interval (CI) on the mean difference in tensile strength.

(a)Assume the samples are paired.