4.8 Your local gym charges nonmembers €20 per visit. If you join the gym, you can use all their equipment and exercise for €10 per visit, but you have to pay an annual fee of F. Use an indifference curve diagram to find the value of F such that you are indifferent between joining and not joining. Suppose that the gym charged you exactly that value of F. Would you go to the gym more or fewer times than if you did not join? For simplicity, assume that the price of all other goods is €1.