The alternating current (AC) breakdown voltage of an insu- lating liquid indicates its dielectric strength. The article "Testing Practices for the AC Breakdown Voltage Testing of Insulation Liquids" (IEEE Electrical Insulation Magazine, 1995: 21-26) gave the accompanying sample observations on breakdown voltage (kV) of a particular circuit under certain conditions. 62 50 53 57 41 53 55 61 59 64 50 55 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. Construct a boxplot of the data and comment on inter- esting features. b. Calculate and interpret a 95% CI for true average break- down voltage μ. Does it appear that u has been precisely estimated? Explain. c. Suppose the investigator believes that virtually all values of breakdown voltage are between 40 and 70. What sam- ple size would be appropriate for the 95% CI to have a width of 2 kV (so that u is estimated to within 1 kV with 95% confidence)?