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?

     

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? 87 Octane 89 Octane 91 Octane Ethanol 5% Ethanol 10% Compact 30.8 30.8 19.5 31.3 27.3 Mid-Size 17.3 18.3 16.9 17.1 31.6 Full-Size 28.9 27.7 15.6 30.2 30.2 SUV 21.8 18.6 20.2 20.2 29.4

Solution

Group           Mean             n        Std. Dev     87 Octane 24.7 4 6.2722     89 Octane 23.85 4 6.3637     91 Octane 18.05 4 2.1641     Ethanol 5% 24.7 4 7.1138     Ethanol 10% 29.625 4 1.797 Total 24.185 20 6.0112     Compact 27.94 5 4.9823     Mid-Size 20.24 5 6.3732     Full-Size 26.52 5 6.1925     SUV 22.04 5 4.2671     Total 24.185 20 6.0112   Two-Factor ANOVA   Source SS df MS F p-value   Treatments (Vehicle Size) 271.498 4 67.8745 2.45 0.091285   Blocks (Fuel Type) 198.5815 3 66.1938 2.17 0.131437   Error 415.0675 15 27.6712 Error Blocks 487.974 16 30.499