Similar to 7.8 Fuel efficiency of Prius: Fueleconomy.gov, the official US government source for fuel economy information, allows users to share gas mileage information on their vehicles. The histogram below shows the distribution of gas mileage in miles per gallon (MPG) from 14 users who drive a 2012 Toyota Prius. The sample mean is 53.3 MPG and the standard deviation is 5.2 MPG. Note that these data are user estimates and since the source data cannot be verified, the accuracy of these estimates are not guaranteed. 6 llIIlI 40 45 50 55 60 65 Mileage (in MPG) There are _ degrees of freedom for this test. The test statistic is: (please round to two decimal places) The p-value for this hypothesis test is: (please round to four decimal places) (c) Calculate a 95% confidence interval for the average gas mileage of a 2012 Prius by drivers who participate on fueleconomy. gov. We are 96 confident that the true population gas mileage of a 2012 Prius by drivers who participate on fueleconomy.gov is between mpg and mpg. (please round to one decimal place)