Hercules Hair Restorer Inc. (HHRI) makes many varieties of hair restoration products which are sold under well-known marketing labels. A single batch contains 10,000 8-oz. bottles and takes two days to make. Typically 15 batches are completed per month, for different brands. Basic cost data for the month of January appears below. Calculate the IRR and Total Marginal Cost.

Hair by Zeus Bottle Batch Cost per Oil, fl. oz. 2 $ 3 January's other expenses Supervision $ 8,000 Lotion, fl. oz. 4 $ 1 Indirect materials Zeus potion, fl. oz. 1/4 $ 24 Alcemena scent 1/16 $ 48 Bottle, cap, label 1 $0.4 Direct labor, hour 50 $ 14 Equipment deprec & repairs Plant manager's salary Utilities $ 2,200 $14,520 $ 6,500 $ 1,800 $33,020 Machine hours 8