15 In Exercise 14, suppose that the owner wishes to consider her decision problem over a 2- day period. Her alternatives for the second day are determined as follows. If the demand in day 1 is equal to the amount stocked, then she will continue to order the same quantity on the second day. Otherwise, if the demand exceeds the amount stocked, then she will have the options to order higher levels of stock on the second day. Finally, if day 1's de- mand is less than the amount stocked, then she will have the options to order any of the lower levels of stock for the second day. Express the problem as a decision tree, and find the optimal solution using the cost data given in Exercise 14.