Question

Using the graph, find the rate of change of a country's population.

Answer 1

The slope of a line that passes through points (x1, y1) and (x2, y2) is given by:

`m=(y_2-y_1)/(x_2-x_1)\text{.}`

The slope gives us the rate of change of a linear function. From the graph, we see that the line passes through points:

`\begin{gathered} (x_1,y_1)=(1991,250), \\ (x_2,y_2)=(1995,270). \end{gathered}`

Replacing these values in the equation above, we get:

`m=(270-250)/(1995-1991)=(20)/(4)=5.`

Answer

The population is growing by 5 million people per year.