I need only question # 7! And please show work

more advanced challenging c. The cost of 50 items is T indicates exercises that should be solved using technology (A) approximately $20 and increasing at a rate of about In Exercises 1-4, for each cost function, find the marginal cost at $3,000 per item. the given production level x, and state the units of measurement. (B) approximately $0.50 and increasing at a rate of about (All costs are in dollars. ) [Hint: See Example 1.] $3,000 per item. (C) approximately $3,000 and increasing at a rate of about 1. C(x) = 10,000 + 5x - 0.0001x2; x = 1,000 $20 per item. 2. C(x) = 20,000 + 7x - 0.00005x2; x = 10,000 (D) approximately $3,000 and increasing at a rate of about 3. C(x) = 15,000 + 100x + 1.000 $0.50 per item. ix = 100 8. A certain cost function has the following graph: 4. C(x) = 20,000 + 50x + 10,000 ;x = 100 8,000 In Exercises 5 and 6, find the marginal cost, marginal revenue, and marginal profit functions, and find all values of x for which 6,000 the marginal profit is zero. Interpret your answer. [Hint: See Example 2.] Dollars 4.000 5. C(x) = 4x; R(x) = 8x - 0.001x2 6. C(x) = 5x2; R(x) = x3 + 7x + 10 2,000 7. A certain cost function has the following graph: X 50 100 150 200 8,000 A Items a. The associated marginal cost is 6,000 (A) increasing, then decreasing. (B) decreasing, then increasing. Dollars 4,000 (C) always increasing. (D) always decreasing. 2,000 b. When x = 100, the marginal cost is (A) greater than (B) less than x 0 50 100 150 200 (C) approximately equal to the average cost. Items c. The cost of 150 items is (A) approximately $4,400 and increasing at a rate of about a. The associated marginal cost is $40 per item. (A) increasing, then decreasing. (B) approximately $40 and increasing at a rate of about (B) decreasing, then increasing. $4,400 per item. (C) always increasing. (C) approximately $4,400 and increasing at a rate of about (D) always decreasing. $1 per item. b. The marginal cost is least at approximately (D) approximately $1 and increasing at a rate of about (A) x = 0. B) x = 50. $4,400 per item. (C) x = 100. (D) x = 150