4. Now suppose that, after a week or so of trading, the students in the class start using M&Ms as money. This situation does not change the stable relative prices that have emerged. a. Identify the formula, presented in one of my lectures and in my lectures notes, that can be used to calculate the total number of absolute prices in an economy. (Hint: Again, see page 13 of my lAB lecture notes.) Then use this formula to calculate the number of absolute prices in the classroom economy. Report these absolute prices, in descending numerical order (highest value to lowest). Hint: The absolute price of a good is the number of units of money needed to buy one unit of the good. You shouldn't have to calculate the absolute prices, because you've already done it as part of the answer to a previous question.)