A car manufacturer is introducing a new model, and they claim that the average fuel consumption for this model is 35 miles or more per gallon on the open road. The competitors believe this estimate is too high. You are employed by a testing agency to run a statistical test and verify the car manufacturer’s claim. You conduct a highway mileage test on 80 cars and save the results in an Excel file. Upload the Excel file CarEfficiency and save it in SPSS data format for future use. The data are available on GAP under the “Supplemental Material” folder. Complete the following tasks and copy your results in a word document and submit your report.
- Examine if the sample data follows a normal distribution using the Explore feature under the Descriptive Statistics in SPSS (or Insert Statistic Chart in Excel).
- Construct a confidence interval for the population mean at 99% confidence level.
- Conduct a test of hypothesis at 1% significance level to verify if the car manufacturer’s claim is justified. State the null and alternative hypotheses in the proper conventional form.