four laborers are needed to replace the output lost by reducing capital by one, and so the marginal rate of technical substitution is equal to 1/4.
four laborers are needed to replace the output lost by reducing capital by one, and so the marginal rate of technical substitution is equal to 4.
four laborers are needed to replace the output lost by reducing capital by one, and so the marginal rate of technical substitution is equal to 4-1=3.
Not enough information is given to solve this problem.