Engineers are testing company fleet vehicle fuel economy mil

Engineers are testing company fleet vehicle fuel economy (miles per gallon) performance by using different types of fuel. One vehicle of each size is tested. Does this sample provide sufficient evidence to conclude that there is a significant difference in treatment means?

Two-Factor Anova Without Replication (Randomized Block Model)

Required information

Solution

Two-way ANOVA: Fuel economy versus Factor 1, Factor 2

Source SS df MS F P
Factor 1 (Vehicle Size) 198.046 3 66.0152 5.74 0.011
Factor 2 (Fuel Type)     284.548 4 71.1370 6.18 0.006
Error 138.112 12 11.5093
Total 620.706 19

Total
Variable Factor 2 Count Mean StDev
(Fuel Type    1 4 22.95 6.25
2 4 25.00 5.73
3 4 18.475 0.842
4 4 23.70 6.15
5 4 30.200 1.283

Total
Variable Factor 1 Count Mean StDev
Vehicle Size    1 5 27.36 4.39
2 5 20.92 6.09
3 5 27.06 4.98
4 5 20.92 4.95

Fuel economy

(Total) 20 24.07 5.72