Yolanda runs a bullfrog farm.When she employs 1 person, she produces 1,000 bullfrogs a week. When she hires a second worker, her total product doubles. Her total product doubles again when she hires a third worker. When she hires a fourth worker, her total product increases but by only 1,000 bullfrogs. Yolanda pays $1,000 a week for equipment and $500 a week to each worker she hires.
At what output is Yolanda's average total cost at a minimum?