please help I'm very confused with this one

9. An automobile manufacturer who wishes to advertise that one of its models achieves 30 mpg (miles per gallon) decides to carry out a fuel efficiency test. Six nonprofessional drivers are selected, and each one drives a car from Phoenix to Los Angeles. The resulting fuel efficiencies (in miles per gallon) are: 27.2, 29.3, 31.2, 28.4, 30.3, and 29.6. Assuming that fuel efficiency is normally distributed under these Circumstances with standard deviation O = 1.408, do the data contradict the claim that true average fuel efficiency is (at least) 30 mpg? Use a = 0.05. [Hint: Use the Z-test for the population mean / ] a. Hypotheses: b. Calculations: Test Statistics: Critical Value P-Value:c. Decision and Conclusion: Decision: Conclusion