When building an operating model for a potential investment, how should a private equity analyst forecast variable and fixed costs differently? 1.Variable costs are linked to the number of employees, while fixed costs are based on the company's assets. 2.Variable costs are estimated using a percentage of revenue or units sold, while fixed costs are forecasted independently of sales volume. 3.Variable costs are forecasted monthly, while fixed costs are forecasted annually. 4.Variable costs are based on industry benchmarks, while fixed costs are based on the company's historical performance