With all of the talk lately about fuel efficient cars, it's important to see car companies live up to their hype.Here are the top five fuel efficient cars.Each car was test driven 5 times on full tanks of gas to see how many miles per gallon they got.The results are as follows

Hyundai Elantra (PREDICTED 33) - 31.2, 29.9, 36.2, 34.5, 30.7

Honda Civic (PREDICTED 30) - 28.8, 31.7, 30.9, 27.6, 29.5

Mazda 3 (PREDICTED 28) - 28.3, 27.9, 28.5, 27.6, 29.0

Ford Focus (PREDICTED 32) - 33.2, 31.7, 34.1, 32.4, 32.0

Toyota Corolla (PREDICTED 30) - 31.2, 29.3, 30.8, 28.9, 31.4

1.)Calculate the variance for each car (to the nearest tenth)! :) The link to the variance formula is in this link: http://www.statisticslectures.com/topics/variancesample/

Hyundai Elantra

• Variance:

Honda Civic

• Variance:

Mazda 3

• Variance:

Ford Focus

• Variance:

Toyota Corolla

• Variance:

For your help, I have listed all of the standard deviations, the only clue that I got from the professor was: Tell you what. You'll know you got the correct variance for the Hyundai Elantra if you get 7.3. That's the correct answer. Then take the square root of the variance and you've got the standard deviation.

Honda Civic

1. Stnd. Dev:=2.14=1.46

Mazda 3

1. Stnd. Dev:=0.23=0.48

Ford Focus

1. Stnd. Dev:=0.76=0.87

Toyota Corolla

1. Stnd. Dev:=1.05

Now that you have the variance and deviation of each car, answer the following questions

4.)Which car company was the most consistent with miles per gallon?How did you know?

5.)Would you use the mean or the standard deviation if you were trying to determine if the car companies were close to their predicted miles per gallon?Explain your reasoning.