Problem 17-30 Joint Costs (LO 17-4, 17-5) [The following information applies to the questions displayed below.] Allegheny River Sawmill manufactures two lumber products from a joint milling process. The two products developed are mine support braces (MSB) and unseasoned commercial building lumber (CBL). A standard production run incurs joint costs of $930.000 and results in 70,000 units of MSB and 108,000 units of CBL. Each MSB sells for $7. and each unit of CBL sells for $12. Problem 17-30 Part 1 Required: 1. Calculate the amount of joint cost allocated to commercial building lumber (CBL) on a physical-units basis. (Round the calculation of relative proportions to four decimal places.) Joint cost allocated to CBL 2. Calculate the amount of joint cost allocated to the mine support braces (MSB) on a relative-sales value basis. (Round the calculation of relative proportions to two decimal places of percentage.) Joint cost allocated to MSB3. Assume the commercial building lumber is not marketable at split-off but must be further planed and sized at a cost of $1,337,400 per production run. During this process, 11,800 units are unavoidably lost; these spoiled units have no value. The remaining units of commercial building lumber are saleable at $27.00 per unit. The mine support braces, although saleable immediately at the split-off point, are coated with a tarlike preservative that costs $420,000 per production run. The braces are then sold for $15.00 each. Using the net-realizable-value basis, compute the completed cost assigned to each unit of commercial building lumber. (Do not round intermediate calculations. Round your answer to 2 decimal places.) Cost per unit of CBL 4. If Allegheny River Sawmill chose not to process the mine support braces beyond the splitoff point, the contribution from the joint milling process would increase or decrease by what amount? The contribution of MSB would