The Following Table Shows the Mileage for Four Different Cars

question 6

Essay

The following table shows the mileage for four different cars and three different brands of gas. Assuming no
effect from the interaction between car and brand of gas, test the claim that the four cars have the same mean
mileage. Use a 0.05 significance level. $\begin{array}{l|lll} & \text { Brand 1 } & \text { Brand 2 } & \text { Brand 3 } \\\hline \text { Car 1 } & 22.4 & 25.2 & 24.3 \\\text { Car 2 } & 19 & 18.6 & 19.8 \\\text { Car 3 } & 24.6 & 25 & 25.4 \\\text { Car 4 } & 23.5 & 23.6 & 24.1\end{array}$

$$\begin{array} { l r c r r c } \text { Source } & \text { DF } & \text { SS } & \text { MS } & \text { F } & \text { p } \\\text { Car } & 3 & 61.249 & 20.416 & 39.033 & 0.000249 \\\text { Gas } & 2 & 2.222 & 1.111 & 2.124 & 0.200726 \\\text { Error } & 6 & 3.138 & 0.523 & & \\\text { Total } & 11 & 66.609 & & &\end{array}$$