A car company claims that their Super Spiffy Sedanaverages 31 mpg. You randomly select 8 Super Spiffies from localcar dealerships and test their gas mileage under similarconditions.
You get the following MPG scores:
| MPG: | 30, | 28, | 32, | 26, | 33, | 25, | 28, | 30 |
We wan to test whether the actual gas mileage for these carsdeviate significantly from 31 (alpha = .05).
1- Are we given the value of the populationmean (ĂŽÂĽ)?
2- What is the the standard error?
3- What is the the null hypothesis?
4- What is the the value of the teststatistic?
5- Based on the p-value you obtained, should wereject the null hypothesis at significance level α = 0.05?
6- What is a 95% confidence interval for themean actual gas mileage of the company's cars?
