Answer:
The gas bill increases by $50
Step-by-step explanation:
We know that the increase in gas bills is directly proportional to the temperature setting. Let's take the increase in gas bills as g and increase in temperature setting as t. Thus, this can be written as:
g ∝ t
In every proportionality, there is a constant k, so it will be:
g = kt
It is mentioned that when the temperature setting increases by 4, the gas bill increases by $20, so in terms of the constant, we can write it as:
20 = k 4
We don't know the value of the constant, so we have to first find it out.
k = 20 ÷ 4
k = 5
Thus,
g = 5t
Now that we know the value of the constant, we can find by how much the gas bill will increase if the temperature setting increases by 10.
g = 5 × 10
g = 50
∴ the gas bill increases by $50 when the temperature setting increases by 10 degrees Fahrenheit.
