Ten measurements of impact energy on specimens of A238 steel at 60 ºC are as follows:
64.1, 64.7, 64.5, 64.6, 64.5, 64.3, 64.6, 64.8, 64.2, and 64.3 J.
(a) Use the Student’s t distribution to find a 95% confidence interval for the impact energy of A238 steel at 60 ºC.
(b) Use the Student’s t distribution to find a 98% confidence interval for the impact energy of A238 steel at 60 ºC.