Which of the following statements is false? If marginal cost is rising, then average variable cost must be rising. The marginal cost of the fifth unit of output equals the total cost of five units...

#12 ch. 13 Can you explain what the correct one is and why? Can you also explain why the other ones are incorrect?

Extracted text: Which of the following statements is false? If marginal cost is rising, then average variable cost must be rising. The marginal cost of the fifth unit of output equals the total cost of five units minus the total cost of four units. The total variable cost of seven units equals the average variable cost of seven units times seven. The marginal cost of the fifth unit of output equals the total variable cost of five units minus the total variable cost of four units.