In the product schedule, total product rises from 330 units (at 3 workers) to 440 units (at 4 workers). The marginal product of the 4th worker is:

1. Marginal product is the change in total product from one more unit of the variable factor: $MP_n = TP_n - TP_{n-1}$. 2. Here $TP_4 = 440$ and $TP_3 = 330$. 3. So $MP_4 = 440 - 330 = 110$ units. 4. The answer is 110 units. _Source: ICAI BoS CA Foundation Paper 4 Business Economics, Ch 3 Unit I "Theory of Production", p.17_