Final answer:
The marginal product of the 12th worker cannot be determined based on the given information.
Step-by-step explanation:
The marginal product of the 12th worker in Lauren's tangerine grove cannot be determined based on the given information. The question only provides the marginal product of the 11th worker, which is 13 bushels of tangerines. To determine the marginal product of the 12th worker, we would need additional information about the productivity of each worker. It is impossible to determine whether the marginal product of the 12th worker will be less than 13 bushels, equal to 13 bushels, more than 13 bushels, or zero bushels without more data.