Where does the marginal cost curve intersect the average total cost curve?

Where does the marginal cost curve intersect the average total cost curve?

• A. At the minimum of ATC.
• B. At the maximum of ATC.
• C. It never intersects.
• D. It is always above ATC.

Answer: (A)

The key idea is how marginal cost relates to the average total cost. If the cost of producing one more unit is below ATC, that extra unit pulls ATC down; if it’s above ATC, it pushes ATC up. The only point where ATC stops falling and starts rising is when MC equals ATC. At that exact quantity, ATC reaches its lowest point, so the intersection occurs at the minimum of ATC. The other statements don’t fit because the ATC curve’s minimum isn’t a maximum, MC isn’t always above ATC, and MC does cross ATC at that single minimum point.

The key idea is how marginal cost relates to the average total cost. If the cost of producing one more unit is below ATC, that extra unit pulls ATC down; if it’s above ATC, it pushes ATC up. The only point where ATC stops falling and starts rising is when MC equals ATC. At that exact quantity, ATC reaches its lowest point, so the intersection occurs at the minimum of ATC. The other statements don’t fit because the ATC curve’s minimum isn’t a maximum, MC isn’t always above ATC, and MC does cross ATC at that single minimum point.