A major oil company has developed a new gasoline additive that is supposed to increase mileage. To test this hypothesis, ten cars are randomly selected. The cars are driven both with and without the additive. The results are displayed in the following table. Can it be concluded, from the data, that the gasoline additive does significantly increase mileage?

Let d=(gasmileagewithadditive)(gasmileagewithoutadditive)d=(gasmileagewithadditive)(gasmileagewithoutadditive). Use a significance level of =0.1=0.1 for the test. Assume that the gas mileages are normally distributed for the population of all cars both with and without the additive.

Car	1	2	3	4	5	6	7	8	9	10
Without additive	20.320.3	27.327.3	24.724.7	14.414.4	17.817.8	20.420.4	22.522.5	1111	22.322.3	12.412.4
With additive	21.321.3	29.829.8	26.626.6	15.515.5	18.218.2	20.720.7	22.822.8	12.612.6	2323	1414

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Step2of5:

Find the value of the standard deviation of the paired differences. Round your answer to two decimal places.