There are three main sources of heat in the deep earth: (1) heat from when the planet formed and accreted, which has not yet been lost; (2) frictional heating, caused by denser core material sinking to the center of the planet; and (3) heat from the decay of radioactive elements. CROSS SECTION shows Earth's structure.
â The operating margin was an especially useful metric or ratio during the meeting as we wanted the discussion to include revenue statistics.
Calculating the Operating Margin. To calculate the operating margin, divide operating income by the total revenue. Operating Income Ã· Sales = Operating Margin. Just as you learned with the gross profit margin, what is considered good depends on the industry. There is one extremely important thing you must learn, though.