please help 1-5

I. In performing CVP analysis for a manufacturing company, what simplifying assumption is usually made about the volume of production and the volume of sales? II. What two arguments tend to justify classifying all costs as either fixed or variable even though individual costs might not behave exactly as classified? III. In cost-volume-profit analysis, what is the estimated profit at the break-even point? IV. Each of two similar companies has sales of $20,000 and total costs of $15,000 for a month. Company A's total costs include $10,000 of variable costs and $5,000 of fixed costs. If Company B's total costs include $4,000 of variable costs and $11,000 of fixed costs, which company will enjoy more profit if sales double? The ability to perform cost profit analysis is a very important skill. What real life questions can be answered with this analysis