Q8 (10 points): Two different types of electrical cable insulation have recently been tested to determine the voltage level at which failures tend to occur. When specimens were subjected to an increasing voltage stress in a laboratory experiment, failures for the two types of cable insulation occurred at the following voltages: Type A: 36 54 44 52 41 37 53 51 Type B: 52 60 64 44 38 48 68 Suppose that it is known that the amount of voltage that cables having type A insulation can withstand is normally distributed with mean MA and variance 0%, whereas the corresponding distribution for type B insulation is normal with mean mg and variance 0%. a . Assumin that 02 = 02 , determine a 95% confidence interval and a 98% confidence interval for A B. 5 A B M u 2 b . Assuming that 02 _ 40 and a2 100, determine a 95% confidence interval and a 97% confidence interval A B for MA MB