Final answer:
The functions for weekly total costs, total revenue, and profit can be written as C(x), R(x), and P(x) respectively. C(150) and C(400) can be found by substituting the values in the total cost function. The marginal profit MP can be found by taking the derivative of the profit function.
Step-by-step explanation:
The function for weekly total costs C(x) for the model DVD player is: C(x) = Total Fixed Costs + (Variable Cost per Unit * Number of Units)
The function for total revenue R(x) for the model DVD player is: R(x) = Price per Unit * Number of Units
The function for profit P(x) for the model DVD player is: P(x) = R(x) - C(x)
To find C(150), substitute the value of 150 into the C(x) function. To find C(400), substitute the value of 400 into the C(x) function.
The marginal profit MP for the model DVD player is the derivative of the profit function P(x) with respect to x. Use calculus to find the derivative of P(x) and evaluate it at a specific value of x.