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Engineers are testing company fleet vehicle fuel economy (miles per gallon) perf

ID: 3127885 • Letter: E

Question

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?

  

Fuel type means differ significantly but vehicle size is not a significant factor.

Fuel type means differ significantly and vehicle size is also a significant factor.

Fuel type means do not differ significantly but vehicle size is a significant factor.

Fuel type means do not differ significantly and vehicle size is not a significant factor.

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?

Explanation / Answer

The excel output for two way ANOVA is shown below:

Since P-values for columns and rows both are less than 0.05, both are significant. The correct option is "Fuel type means differ significantly and vehicle size is also a significant factor."

Anova: Two-Factor Without Replication SUMMARY Count Sum Average Variance   Compact 5 139.9 27.98 21.107   Mid-Size 5 104.3 20.86 15.128   Full-Size 5 138.2 27.64 19.163   SUV 5 112.5 22.5 28.765 87 Octane 4 99.3 24.825 36.10917 89 Octane 4 95.1 23.775 26.1825 91 Octane 4 81.2 20.3 0.986667 Ethanol 5% 4 100.5 25.125 48.03583 Ethanol 10% 4 118.8 29.7 5.333333 ANOVA Source of Variation SS df MS F P-value F crit Rows 194.8975 3 64.96583 5.028153 0.017454 3.490295 Columns 181.607 4 45.40175 3.513954 0.040428 3.259167 Error 155.045 12 12.92042 Total 531.5495 19