4. The fuel economy sticker on a new SUV's window sticker indicates the owner can expect 16 mpg in city driving, 20 mpg highway driving and 18 mpg overall. Accurate gasoline records for one such vehicle were kept, and a random sample of mileage per tank for 50 fill-ups of gasoline was collected: 17.6 17.7 18.1 22.0 17.0 19.4 18.9 17.4 21.0 19.2 18.3 19.1 20.7 16.7 19.4 18.2 18.4 17.1 17.4 15.8 17.9 18.0 16.3 17.5 17.3 20.4 19.1 21.0 18.1 19.0 19.6 18.9 16.8 18.2 17.6 19.1 18.0 16.8 20.9 17.9 17.7 20.3 18.6 19.0 16.5 19.4 18.6 18.6 17.3 18.7 a. (1 point) Can we consider the data to be normally distributed? Explain. b. (2 points) Calculate the sample mean and standard deviation for this data. Round your answers to three decimal places. c. (1 point) Calculate a 95% confidence interval for this data set. d. (1 point) Interpret your interval in the context of the