If the monthly cost for 23 hcf is $48.81, what is the monthly cost for 18 hcf?

Write and solve an equation of ratios, as follows:

$48.81 x

=

23 HCF 18 HCF

Cross-multiplying, we get (23 HCF) x = ($48.81) * (18 HCF).

Solving, this results in x = $38.20 ( monthly cost for 18 HCF)

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.