STEP-BY-STEP ANSWER:
Step 1: Recognize that the Cobb-Douglas function is Q = L^0.5 * K^0.5.
Step 2: The marginal product of labor (MPL) is the partial derivative of Q with respect to L. For L^0.5, differentiate to get (0.5) * L^(-0.5). Multiply by K^0.5, yielding MPL = 0.5 * L^(-0.5) * K^0.5.
Step 3: Substitute L = 16 and K = 9 into the formula. Calculate L^(-0.5) = 1/sqrt(16) = 1/4 and K^0.5 = sqrt(9) = 3.
Step 4: Compute MPL = 0.5 * (1/4) * 3 = 0.5 * 0.25 * 3 = 0.375.
Final Answer: The marginal product of labor is 0.375.