Answer:
≈ $138
Step-by-step explanation:
let h be heating bill and t be average outdoor temperature
Given h varies inversely with t then the equation relating them is
h = [tex]\frac{k}{t}[/tex] ← k is the constant of variation
To find k use the condition h = 190 and t = 40 , then
190 = [tex]\frac{k}{40}[/tex] ( multiply both sides by 40 )
7600 = k
h = [tex]\frac{7600}{t}[/tex] ← equation of variation
When t = 55 , then
h = [tex]\frac{7600}{55}[/tex] ≈ 138.1818
That is monthly heating bill is approximately $138 ( to nearest whole number )
