4.2 Tshebo Cleaning Supplies manufactures cleaning products for households and industrial use. One of the key substance of their abrasives is ordered at a supplier in Russia. Due to the disturbances in supply chain, the project manager for the process is trying to decide whether the company should now make the substance in-house or continue buying it from the supplier. Below are estimated costs and units required: Make Buy Annual volume 80 000Kg 80 000Kg Fixed cost/year R230 000 - Variable cost/unit R44 R55 4.2.1 Should the company buy or make the component in-house? (Show all your calculations) (4)