Question

Determine if the function is proportional. Explain your reasoning.

Answer 1

Answer: Third option.

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
`(0,0)`).

Then, Direct proportional functions have the following form:

`y=kx`

This shows that two quantities vary directly with each other.

"k" is the constant of proportionality.

Solving for "k", you get this ratio:

`k=(y)/(x)`

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:

`k=(y)/(x)=( Number\ of\ People)/( Number\ of\ Generation)`

Therefore, this ratio is the same for every pair of values.