A monopolist faces a demand curve given by P = 30-Q and has constant marginal (and average cost) of $19. What is the economic profit made by this profit-maximising monopolist when practicing perfect price discrimination? [Round your answer to 2 decimal places where necessary]

To find the economic profit made by a profit-maximising monopolist when practicing perfect price discrimination, we need to follow these steps:

1. First, we need to find the quantity where the marginal cost (MC) equals the marginal revenue (MR). In this case, the marginal cost is constant at $19.

2. The demand curve is given by P = 30 - Q. To find the marginal revenue, we need to find the derivative of the revenue function (R = PQ). However, under perfect price discrimination, the monopolist captures all consumer surplus, so the marginal revenue is simply the price at each quantity, which is given by the demand curve.

3. Set MC = MR to find the quantity. So, 19 = 30 - Q. Solving for Q gives Q = 11.

4. The total revenue under perfect price discrimination is the area under the demand curve up to the quantity Q. This is given by the integral of the demand curve from 0 to Q, which is ∫(30 - Q)dQ from 0 to 11. This equals (30Q - 0.5Q^2) from 0 to 11, which is $275.

5. The total cost is the marginal cost times the quantity, which is $19 * 11 =$209.

6. The economic profit is the total revenue minus the total cost, which is $275 -$209 = $66.

So, the economic profit made by this profit-maximising monopolist when practicing perfect price discrimination is $66.

To find the economic profit made by a profit-maximising monopolist when practicing perfect price discrimination, we need to follow these steps:

Step 1: Find the quantity where Marginal Cost (MC) equals Marginal Revenue (MR). In this case, the MC is constant at $19. The MR is found by taking the derivative of the total revenue (TR), which is P*Q.

Given the demand curve P = 30 - Q, we can write TR as (30-Q)*Q = 30Q - Q^2. The derivative of this is 30 - 2Q.

Setting MC equal to MR gives us 19 = 30 - 2Q. Solving for Q gives us Q = 5.5.

Step 2: Find the total revenue (TR) at this quantity. Substituting Q = 5.5 into the demand curve gives us P = 30 - 5.5 = 24.5. So, TR = PQ = 24.55.5 = $134.75.

Step 3: Find the total cost (TC) at this quantity. Since the cost is constant at $19, TC = MC*Q = 19*5.5 =$104.5.

Step 4: Subtract the total cost from the total revenue to find the economic profit. So, Profit = TR - TC = $134.75 -$104.5 = $30.25.

So, the economic profit made by this profit-maximising monopolist when practicing perfect price discrimination is $30.25.