A taxi company manager is trying to decide whether the use of radial tires instead of regular belted tires improves fuel economy. Twelve cars were equipped with radial tires and driven over a prescribed test course. Without changing drivers, the same cars were then equipped with regular belted tires and driven once again over the test course. The gasoline consumption, in kilometers per liter, was recorded in the accompanying table. Can it be concluded that cars equipped with radial tires give better fuel economy than those equipped with belted tires? Assume the populations to be normally distributed. Use a P-value in your conclusion. Use a level of significance of 0.10.

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Let sample 1 be the results from the radial tires and let sample 2 be the results from the belted tires. Let the differences be the sample 1 results minus the sample 2 results. State the null and alternative hypotheses.

Ho Ho = 0

> 0

(Type integers or decimals. Do not round)

Find the test statistic

The test statistic is (Round to two decimal places as needed.)