Foggy Optics, Inc. makes laboratory microscopes. Setting up each production run costs $2400. Insurance costs, based on the average number of microscopes in the warehouse, amount to $10 per microscope per year. Storage costs, based on the maximum number of microscopes in the warehouse, amount to $10 per microscope per year. Suppose that the company expects to sell 4000 microscopes at a fairly uniform rate throughout the year. Determine the number of production runs that will minimize the overall expenses for the company. The number of runs is