3. The alternating current (AC) breakdown voltage of an insulating liquid indicates its dielectric strength. The accompanying sample observations on breakdown voltage (kV) of a particular circuit under certain conditions is as follows: 62 50 53 57 41 53 55 61 59 64 50 53 64 62 50 68 54 55 57 50 55 50 56 55 46 55 53 54 52 47 47 55 57 48 63 57 57 55 53 59 53 52 50 55 60 50 56 58 (a) Calculate and interpret a 95% CI for the true average breakdown voltage µ. (b) Suppose the investigator believes that virtually all values of breakdown voltage are between 40 and 70, using a conservative estimate of s = 70−40 4 = 7.5. What sample size would be appropriate for the 95% CI to have a width of 2 kV