Willis Cosmetics produces a variety of cosmetics and hair care products. One popular shampoo is produced at the company's Genoa Street Plant (GSP). The financial staff are in the process of revising the estimates for overhead and looking at different approaches. After much discussion, the staff selected direct labor costs as the best cost driver to explain overhead cost. The staff have collected monthly data on direct labor and overhead costs at GSP for the most recent fiscal year. The data follow: Required: a. Estimate the monthly fixed costs and the unit variable cost percentage of direct labor cost using the high-low estimation method. Note: Enter negative values with a minus sign