Answer:
One tailed
To conclude if there is an increase in the mean gas mileage due to new type of tire.
Explanation:
We are given the following in the question:
The manufacture wants to compare increase in the mean gas mileage.
Population mean = 32 miles per gallon
Thus, the manufacture could carry a hypothesis test to compare mean.
A one tailed test (z-test or t-test) based on the information can be used to compare the increase in mean.
Thus,
The automotive manufacturer should perform a one tailed hypothesis test to conclude if there is an increase in the mean gas mileage due to new type of tire.