could you also include the degrees of freedom if there is one

An industrial plant wants to determine which of two types of fuel, electric or gas, is more cost efcient (measured in cost per unit of energy]. Independent random samples were taken of plants using electricity and plants using gas. These samples consisted of 7 plants using electricity, which had a mean cost per unit of $47.24 and standard deviation of 88.13, and 12 plants using gas, which had a mean of $60.20 and standard deviation of $8.51 Assume that the populations of costs per unit are normallv distributed for each type of fuel, and assume that the variances of these populations are equal. Can we conclude, at the 0.0] level of signicance, that the mean cost per unit for plants using electricity, ul, is less than the mean cost per unit for plants using gas, 1.12? Perform a onetailed test. Then ll in the table below. Carry your intermediate computations to at least three decimal places and round 1irour answers as specified in the table. [If necessary, consult a list of formulas.) V The alternative hypothesis: The type of test statistic: (Choose one) v The value of the test statistic: (Round to at least three decimal places.) The p-value: (Round to at least three decimal places.) Can we conclude that the mean cost per unit for plants using electricity is less than the mean cost 0 Yes O No per unit for plants using gas