Question

A monthly water bill (in dollars) is a linear function of the amount of water the hose uses (in hundreds of cubic feet, HCF) the function uses the slope of 1.45
If the monthly cost for 17 HCF is $44.39, what is the monthly cost for 11 HCF ?

Answer 1

Answer:

The monthly cost for 11 HCF would be $ 35.69.

Explanation:

Consider the linear function that represents the amount of water ( in dollars ) for x HCF of used water,

y = mx + c

Where, m is the slope of the function,

We have, m = 1.45,

So, the function would be,

y = 1.45x + c

If y = $ 44.39 and x = 17,

This implies,

            44.39 = 1.45(17) + c

            44.39 = 24.65 + c

44.39 - 24.65 = c

             19.74 = c

Thus, the required equation that shows the amount of water for x HCF of water is,

y = 1.45x + 19.74

For x = 11 HCF,

The amount of water for 11 HCF of water,

y = 1.45(11) + 19.74

y = 15.95 + 19.74

y = 35.69

Hence, the monthly cost for 11 HCF would be $ 35.69.