<h3>
Answer: 2.2</h3>
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Explanation:
The population was 313 million and it jumped up to 324 million. This is an increase of 324-313 = 11 million
Divide this over 5, since this is the span of time from 2012 to 2017 (ie 2017-2012 = 5)
We get (11 million)/5 = 2.2 million
We basically divide 11/5 to get 2.2, then stick "million" at the end.
The average rate of change is 2.2 million people per year. This means that every year, on average, the population is going up by 2.2 million people.
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Effectively, we just computed the slope through the points (2012,313) and (2017,324)
Note how using the slope formula gets us to the same result
m = slope
m = rise/run
m = (change in population)/(change in time)
m = (change in y)/(change in x)
m = (y2-y1)/(x2-x1)
m = (324-313)/(2017-2012)
m = 11/5
m = 2.2
The same idea applies if you tacked on "million" to each of the proper values mentioned.