Question

A study is done to compare the fuel efficiency of cars. The first group of cars generally get about 38 miles per gallon. The second group of cars generally get about 24 miles per gallon. Based on the mean values of each​ group, what inference can be​ made? What else might a person conclude from the mean​ values?
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Part 1
Which of the following is a correct inference based on the mean​ values?
A.The cars in group 1 generally are more fuel efficient.
The cars in group 1 generally are more fuel efficient.
Your answer is correct.B.The cars in group 1 and group 2 are equally fuel efficient.
The cars in group 1 and group 2 are equally fuel efficient.
C.The cars in group 2 generally are more fuel efficient.
The cars in group 2 generally are more fuel efficient.
Part 2
Which of the following is another conclusion that a person might make from the mean​ values?
A.The cars in group 2 are smaller.
The cars in group 2 are smaller.
B.The cars in group 1 are smaller.
The cars in group 1 are smaller.
C.The cars in each group are about the same size.
The cars in each group are about the same size.
Which of the following is a correct inference based on the mean values?Which of the following is another conclusion that a person might make from the mean values?

Answer 1

Part 1: A. The cars in group 1 generally are more fuel efficient.
- The mean mpg is 38 vs. 24, so on average group 1 gets more miles per gallon.

Part 2: B. The cars in group 1 are smaller.
- Higher mpg is often associated with smaller, lighter cars, so that is a plausible conclusion from the means.
- Caveat: the mean alone doesn’t prove this — other factors (engine type, driving conditions, sample size, variability, etc.) could explain the difference. Statistical tests and more information about the samples would be needed for stronger conclusions.