Sometimes questions that involve graphs will ask you to consider the effect of a changing factor or factors.

Problem statement:

The line labeled

D1

in the graph to the right shows the number of cups of lemonade that Caroline and Emily can sell at their lemonade stand at various prices. Caroline and Emily have noticed that they sell more lemonade when it's hotter.

Click anywhere on the graph to open a window with a control labeled Temperature. If you use the slider to change the temperature, the line will shift. Change the temperature from 80 degrees to

100

degrees.

Question:

At a price of $0.50, how many more or fewer cups of lemonade do Caroline and Emily sell when the temperature is

100

degrees than when the temperature is 80 degrees?

(Note: indicate the change in cups of lemonade sold: fewer will be a negative number and more will be a positive number)

A.

0

B.

-2

C.

10

D.

15

.....

Lemonade Sales

0510152025300.000.250.500.751.001.251.501.752.002.252.50CupsoflemonadesoldperdayPrice

D1