Come-Clean Corporation produces a variety of cleaning compounds and solutions for both industrial and household use. While most of its products are processed independently, a few are related, such as the company's Grit 337 and its Sparkle silver polish. Grit 337 is a coarse cleaning powder with many industrial uses. It costs $1.20 a pound to make, and it has a selling price of $10.60 a pound. A small portion of the annual production of Grit 337 is retained in the factory for further processing. It is combined with several other ingredients to form a paste that is marketed as Sparkle silver polish. The silver polish sells for $6.00 per jar. This further processing requires one-fourth pound of Grit 337 per jar of silver polish. The additional direct variable costs involved in the processing of a jar of silver polish are: Other ingredients Direct labor Total direct cost $ 0.55 1.36 $ 1.91 Overhead costs associated with processing the silver polish are: Variable manufacturing overhead cost Fixed manufacturing overhead cost (per month) Production supervisor Depreciation of mixing equipment 25% of direct labor cost $3,400 $ 1,500