pls help with hw question

Some people believe that higher-octane fuels result in better gas mileage for their car. To test this claim, a researcher randomly selected 11 individuals to participate ity in the study. Each participant received 10 gallons of gas and drove his car on a closed course. The number of miles driven until the car ran out of gas was recorded. A coin flip was used to determine whether the car was filled up with 87-octane or 92-octane first, and the driver did not know which fuel was in the tank. Complete parts (a) through (e). Click here to view the data, probability plots, and technology output. Click here to view the table of critical values for the correlation coefficient. . . . . . O D. Yes, both variables are normally distributed. (d) The differences are computed as 92-octane minus 87-octane. The normal probability plot of the differences is shown. The correlation between the differenced data and the expected z-scores is 0.971. Is there reason to believe that the differences are normally distributed? tents Yes, since the correlation coefficient is greater than the critical value. (e) The researchers used a statistical software package to determine whether the mileage from 92-octane is greater than the mileage from 87-octane. What do you conclude at a = 0.05? Why? Begin by writing the hypotheses. ccess Ho: The difference in mileage for 92-octane and 87-octane equals zero. H, : The difference in mileage for 92-octane and 87-octane is greater than zero. a Library The test statistic is