all . Making zero economic profit is bad. True False WE cannot comment unless we know the explicit and implicit costs correctly. Which one is correct? 6. Example of an implicit cost is when owners don't pay salary to themselves when owners pay salary to themselves when owners don't pay salary to the employees Which one is correct? 7. A tax rise on production will shift the average total cost curve downward upward there will be no change it will change only the total cost curve Which one is correct? 8. Marginal cost is a reflection of the marginal physical product of the variable input. True False They are parallel they are not comparable Which one is correct? 9. Marginal cost is equal to total cost divided by total output produced total cost divided by change in output produced change in total cost divided by the total output produced change in total cost divided by change in output produced Which one is correct