Joan grows pumpkins. if joan plants no seeds on her farm, she gets no harvest. if she plants 1 bag of seeds, she gets 500 pumpkins. if she plants 2 bags, she gets 800 pumpkins. if she plants 3 bags, she gets 900 pumpkins. a bag of seeds costs $100, and seeds are her only cost. joan's production function exhibitsa. increasing marginal product. b. decreasing marginal product. c. constant marginal product. d. any of the above could be correct.

Option (B) is correct.

Explanation:

Correct option: Decreasing marginal product.

Marginal product is the change in the level of output, when there will be an extra input employed in the production of a certain commodity.

So, Marginal Product =

Where,

Q = Output

I = Input

Marginal product of 1st bag = 500

Marginal product of 2nd bag =   = 300

Marginal product of 3rd bag =   = 100

∴ From the above calculations, we can seen that as we employed one more bag of seeds as a result marginal product goes on diminishing.

Hence, Joan's production function exhibits decreasing marginal product.