Question

The average fleet-wide performance of light duty trucks has made constant improvement since 1980. For example, the time for the average 1080 light-duty truck to accelerate from 0 to 60 mph was about 14.5 seconds. For 2005 models, that time was only 10.5 seconds.

A) Let m be the model year of a light-duty truck and T be the time in seconds for it to accelerate from 0 to 60 mph. Write a linear function T(m) to model the situation.


B) Use your answer to part (A) to predict the time it will take the average light-duty truck to accelerate from 0 to 60 mph in 2015, if the trend continues.

Answer 1

A) T(m) = -0.16m +331.3

B) T(2015) = 8.9 . . . seconds

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The linear regression function of a graphing calculator can find the equation of the line easily. Or, you can use the 2-point form of the equation of a line.
.. T(m) = (10.5 -14.5)/(2005 -1980)*(m -1980) +14.5
.. T(m) = -0.16(m -1980) +14.5