Question 122730: This is homework and again, I need help!!
A research firm wants to compare the miles per gallon of unleaded regular, mid-grade,and super premium gasolines. Because of differences in the performance of different automobiles, seven different automobiles were selected and treated as blocks. Therefore, each brand of gasoline was tested with each type of automobile. The results of the trials, in miles per gallon, are shown in the following table. At the .05 significance level, is there a difference in the gasolines and automobiles?
Automobile Reg Mid. Super
1 21 23 26
2 23 22 25
3 24 25 27
4 24 24 26
5 26 26 30
6 26 24 27
7 28 27 32
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A research firm wants to compare the miles per gallon of unleaded regular, mid-grade,and super premium gasolines. Because of differences in the performance of different automobiles, seven different automobiles were selected and treated as blocks. Therefore, each brand of gasoline was tested with each type of automobile. The results of the trials, in miles per gallon, are shown in the following table. At the .05 significance level, is there a difference in the gasolines and automobiles?
Automobile Reg Mid. Super
1 21 23 26
2 23 22 25
3 24 25 27
4 24 24 26
5 26 26 30
6 26 24 27
7 28 27 32
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You need to run a ANOVA (analysis of variance) test.
Hopefully you have software or a calculator to do this.
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Ho: The Reg, Mid, and Super results are the same
Ha: At least one of them is different.
alpha = 0.05
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I ran the ANOVA function on a TI calculator and got
a p-value = 0.0251
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Conclusion: Since the p-value is less than alpha,
reject Ho; at least one of the car results is
significantly different than the others.
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Cheers,
Stan H.
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