(Table) Using the information in the table, the equation that represents the relationship between temperature (T) on the horizontal axis and hot chocolate (C) sales on the vertical axis would be
A) C = 150 - 2T
B) C = 50 - 1/2T
C) T = 75 - 2C
D) T = 25 - 1/2C

Question

(Table) Using the information in the table, the equation that represents the relationship between temperature (T) on the horizontal axis and hot chocolate (C) sales on the vertical axis would be 
A) C = 150 - 2T 
B) C = 50 - 1/2T 
C) T = 75 - 2C 
D) T = 25 - 1/2C

Quizplus · Accepted Answer

Looking at the table, we notice that as the temperature increases, the sales of hot chocolate decrease. This suggests an inverse relationship between temperature and hot chocolate sales. 
We can also see that as the temperature increases by 1 degree, the hot chocolate sales decrease by 2. This tells us that the slope of the equation should be -2. 
Using the point-slope formula, where y-y1=m(x-x1), we can use any point from the table, such as (70,140), as (x1,y1). 
Plugging in the values for m and (x1,y1), we get: 
C - 140 = -2(T - 70) 
Simplifying, we get: 
C = -2T + 280 + 140 
C = -2T + 420 
Rearranging to the slope-intercept form, we get: 
C = -2T + 420 
This matches choice A, C = 150 - 2T, with the constants flipped. Therefore, the correct answer is A, C = 150 - 2T.

(Table) Using the Information in the Table, the Equation That