Ivanhoe Productions Limited manufactures and sells three different products of different qualities. They are referred to as: Normal, High, and Superior. The accounting department provides the following information on these products: Determine the contribution margin per machine hour. (Round answers to 2 decimal places, e.g. 15.25.) If the limited resource can be increased by 680 hours, calculate the maximum increase in contribution margin. Assume that Ivanhoe can sell all products manufactured