Barney decides to quit his job as a corporate accountant (which pays $10,000 a month) and go into business for himself as a certified public accountant. he decides not to rent office space downtown, but instead sets up shop in his converted garage apartment, which he could rent out for $300 a month if he wasn’t using it as his own office. he must purchase office supplies worth $75 a month, and his monthly electricity bill has increased by $50 now that he is working out of his home office. after six months of working from home, barney has earned an average of $12,000 per month. a. what are barney’s monthly explicit costs? b. what are barney’s monthly implicit costs? c. what are barney’s monthly economic costs?