A new gasoline additive is supposed to make gas burn more
cleanly and increase gas mileage in the process. Consumer
Protection Anonymous conducted a mileage test to confirm this. They
took a sample of their cars, filled it with regular gas, and drove
it on I-94 until it was empty. They repeated the process using the
same cars, but using the gas additive. Using the data they found,
they performed a paired t-test with data calculated as (with
additive - without additive) with the following hypotheses: Null
Hypothesis: μD ≤ 0, Alternative Hypothesis:
μD > 0. If they calculate a p-value of 0.2143 in
the paired samples t-test, what is the appropriate conclusion?
1)
The average difference in gas mileage is significantly larger
than 0. The average gas mileage was higher with the additive.
2)
The average difference in gas mileage is less than or equal to
0.
3)
We did not find enough evidence to say the average difference
in gas mileage was not 0. The additive does not appear to have been
effective.
4)
We did not find enough evidence to say there was a
significantly negative average difference in gas mileage. The
additive does not appear be effective.
5)
We did not find enough evidence to say there was a
significantly positive average difference in gas mileage. The
additive does not appear to be effective.