Question

Plz help me!!!

Emma notices that the amount owed on her monthly heating bill varies inversely with the average outdoor temperature. Last month the average outdoor temperature was 40°F, and her bill was $190. If this month's average outdoor temperature is 55°F, what will Emma’s monthly heating bill be?

Answer 1

≈ $138

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 =
`(k)/(t)` ← k is the constant of variation

To find k use the condition h = 190 and t = 40 , then

190 =
`(k)/(40)` ( multiply both sides by 40 )

7600 = k

h =
`(7600)/(t)` ← equation of variation

When t = 55 , then

h =
`(7600)/(55)` ≈ 138.1818

That is monthly heating bill is approximately $138 ( to nearest whole number )