Question

Suppose that a household's monthly water bill (in dollars) is a linear function of the amount of water the household uses (in hundreds of cubic feet, HCF). When graphed, the function gives a line with a slope of 1.35 . See the figure below.

If the monthly cost for13 HCF is 25.43$ , what is the monthly cost for 19 HCF?

Answer 1

well th equation will be in the form

Bill = m*HCF + b

you know m = 1.35 and you know you have a data point HCF = 13 and Bill = 25.43

you can use this information to find b, there the line cuts the vertical axis.

25.43 = 1.35 * 13 + b

the value of b is 7.88.

so the linear equation is

Bill = 1.35 * HCF + 7.88

For 19 HCF just substitute it into the above equation and get the cost of the bill.

Answer 2

oops forgot to say ,

in the equation

Bill = m*HCF + b m is the slope of the line.

Answer 3

what the answer

Answer 4

just substitute 19 for HCF and then solve for the bill..

Answer 5

33.53$

Answer 6

well done.

Answer 7

:)