 OK, the old furnace runs at about 68% efficiency in this problem. This is 5.6. And the old furnace runs at an efficiency of E equal to 0.68. And we have the actual cost per unit price or unit fuel, which is $1.02 per gallon. And we also know the calorific value or heating value in millions of BTUs. When you burn one gallon of oil, we get 0.13 million BTUs. So we apply the same formula to get the actual cost, which is cost per unit fuel, which is $1.02 per gallon divided by the heating value, which is 0.13 million BTUs per gallon. We have to have the same units here. And times the efficiency here. Efficiency is 0.68 gallons, and gallons are canceled. And we get this one as $11.50 per million BTUs.