Question

The graph shows the amount of money in Amy's bank account and her spending activity. Does the graph show a proportional relationship?

A. Yes, it is proportional because it has a constant rate of change.

B. No, it is not proportional because it has a constant rate of change.

C. Yes, it is proportional because it has a y-intercept.

D. No, it is not proportional because it has a y-intercept that is not zero.

Answer 1

Yes, it is proportional because it has a constant rate of change. (Option A).

How to calculate the relationship of the graph?

The relationship of the variables presented in the graph is determined by applying the following method as shown below.

The rate of change of the graph is calculated as follows;

m = change in y - value / change in x - value

m = (change in number of dollars ) / ( change in number of days)

m = ( 0 - 25 ) / ( 5 - 0 )

m = - 25 / 5

m = -5 dollars per day

So the relationship between the amount of money in Amy's bank account and her spending activity is - 5 dollars per day.

This implies that her money reduces by 5 dollars every day.

Hence the relationship is proportional since this change is constant.

Answer 2

Option A:

Yes, it is proportional because it has a constant rate of change.

Explanation:

One trick you can use to easily tell a proportional graph is that it follows a straight line. It does not matter whether the line slopes downwards or upwards. The fact that it is straight and not cured at any point, should hint you that the graph is proportional.

Proportional graphs have a constant rate of change. The value of the slope calculated when using any two (x, y) coordinates are the same for any point along the line.