SOLUTION: Problem Page The monthly cost (in dollars) of water use is a linear function of the amount of water used (in hundreds of cubic feet, HCF). The cost for using 13 HCF of water is $3

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Problem Page The monthly cost (in dollars) of water use is a linear function of the amount of water used (in hundreds of cubic feet, HCF). The cost for using 13 HCF of water is $3      Log On


   

Question 1073319: Problem Page
The monthly cost (in dollars) of water use is a linear function of the amount of water used (in hundreds of cubic feet, HCF). The cost for using 13 HCF of water is $35.55 and the cost for using 36 HCF is $73.50. What is the cost for using 16 HCF of water?
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39628) About Me  (Show Source):
You can put this solution on YOUR website!
Two points on the line are (13, 35.55) and (36, 73.50).
What is the missing value, (16, v)?


Two choices. Linear interpolation, or equation of the line containing the two described points. The solution used here will be equation of the line.

y-35.55=%28%2873.5-35.55%29%2F%2836-13%29%29%28x-13%29, which is in the point-slope form. Cost here is y.

y-35.55=%2837.95%2F23%29%28x-13%29
y-35=%281.65%29%28x-13%29
y=1.65x-%281.65%29%2A13%2B35.55
highlight_green%28y=1.65x%2B14.1%29


Cost for 16 HCF of water?
x=16.
highlight%28y=1.65%2A16%2B14.1=highlight%2840.5%29%29

Answer by MathTherapy(10556) About Me  (Show Source):
You can put this solution on YOUR website!
Problem Page
The monthly cost (in dollars) of water use is a linear function of the amount of water used (in hundreds of cubic feet, HCF). The cost for using 13 HCF of water is $35.55 and the cost for using 36 HCF is $73.50. What is the cost for using 16 HCF of water?
Cost to use 16 HCF of water: highlight_green%28%22%2440.50%22%29.

It's TOTALLY RIDICULOUS and SO, SO BIZARRE that one in his right mind would think that 16 HCF would cost MORE than 36 HCF. 

I wish this person would just STOP! STOP misleading people who ask for help.

What is this person achieving by leading people astray and giving wrong answers 99.9% of the times. OMG!!



Is he for real?

Cost for 16 HCF of water?

x=16.

highlight%28y=82.85%29