35. Hybrid or EV? In an attempt to reduce their carbon footprint, many consumers are purchasing hybrid, plug-in hybrid, or electric cars. Consumer Reports ranks the Chevrolet Bolt first among electric cars, with an EPA rating of 238 miles between battery charges, although others report a range between 190 and 313 miles!10 To test this claim, suppose that n535 road tests were conducted and that the average miles between charges was 232 miles with a standard deviation of 20.2 miles.

a. Construct a 95% confidence interval for m, the average time between battery charges for the Chevrolet Bolt.

b. Does the confidence interval in part a confirm the EPA’s claim of 238 miles per battery charge? Why or why not?