Answer: Third option.
Step-by-step explanation:
By definition, the graph of a proportional function is a straight line that passes through the origin (This means that the line passes trough the point [tex](0,0)[/tex]).
Then, Direct proportional functions have the following form:
[tex]y=kx[/tex]
This shows that two quantities vary directly with each other.
"k" is the constant of proportionality.
Solving for "k", you get this ratio:
[tex]k=\frac{y}{x}[/tex]
Observe the graph of the function.
The x-values represents the Number of Generations and the y-values represents the Number of People in millions.
Notice that the graph is a straight line that passes trough the origin. This means that it is a Directly proportional function. Then, its constant of proportionality is:
[tex]k=\frac{y}{x}=\frac{ Number\ of\ People}{ Number\ of\ Generation}[/tex]
Therefore, this ratio is the same for every pair of values.
