A mileage test is conducted for a new car model, the "Pizzazz." Twenty five (n=25) random selected Pizzazzes are driven for a month and the mileage is carefully measured in each. The mean mileage for the sample is 28.6 miles per gallon (mpg) and the sample standard deviation is 2.2 mpg. Determine the test statistic for testing the hypothesis that the population mean is 27 mpg (H0 : =27 Ha :27 )

a. t = 3.56 b. t = 4.6 c. t = 1.96 d. None of the above