Question

a scientist decides to compare the speed (mph) of a particular vehicle with the mileage (miles per gallon). the results are provided below.
predict what the mileage will be at 90mph. round to the nearest tenth.
mileage =
type your answer... mpg

Explanation:

Step1: Enter data into calculator

Enter the speed (x - values: 15, 25, 35, 45, 55, 65, 75) and mileage (y - values: 22.3, 27.5, 28.8, 29.9, 30.4, 27.4, 23.3) into a graphing calculator or statistical software.

Step2: Find the regression equation

Using the linear regression function, we get the equation \(y = - 0.13x+30.25\) (approximate values from regression analysis).

Step3: Predict at \(x = 90\)

Substitute \(x = 90\) into the regression equation: \(y=-0.13\times90 + 30.25\).

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Step4: Round to the nearest tenth

Rounding \(18.55\) to the nearest tenth gives \(18.6\).

Answer:

18.6