Question

In 2015, Ed spent $800 buying lunches. In 2017, he spent $550 buying lunches. What was the rate of change from 2015 to

Answer 1

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Answer:

  $125 per year

Step-by-step explanation:

In the 2 years from 2015 to 2017, the spending on lunches increased by ...

  $800 -550 = $250

That is an average per year of ...

  $250/(2 yr) = $125/yr . . . . average dollar increase per year

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Additional comment

For costs, it is often true that they follow an exponential curve, not a linear one. Ed's spending increased by a factor of 800/550 = 16/11 in the two years, so an average percentage increase of √(16/11) -1 = 20.6% per year.