The scatter plot below shows how the number of posters sold each day at a museum is related to the cost per poster.

Question

The museum manager drew the line of best fit on the scatter plot. Which statement BEST interprets the meaning of the y-intercept of the line of best fit?

A.
For each $1 increase in the price of the posters, about 1 fewer poster is sold.

B.
If the posters cost $40 each, the number sold is about 0.

C.
For each $1 increase in the price of the posters, about 1 more poster is sold.

D.
If the posters are free, about 40 posters are given away.

Answer 1

To interpret the meaning of the y-intercept of the line of best fit in a scatter plot that shows the relationship between the number of posters sold and the cost per poster, we need to focus on what the y-intercept represents.

The y-intercept is the point where the line crosses the y-axis, which corresponds to the value of the dependent variable (number of posters sold) when the independent variable (cost per poster) is zero.

Therefore, the best interpretation of the y-intercept in this context would be:

D. If the posters are free, about 40 posters are given away.

This indicates that when the cost of the posters is $0, approximately 40 posters are expected to be sold.