题目如下：

Existingmachine was purchased 2 years ago at a cost of $3,200.  It is being depreciated straight line overits 8 year life.  It can be sold now for$3,000 or used for 6 more years at which time it will be sold for an estimated$500.  It provides revenue of $5,000annually and cash operating costs of $2,000 annually.

Areplacement machine can be purchased now for $7,800.  It would be used for 6 years, and depreciatedstraight line.  It will result inadditional sales revenue of $1,500 annually, but because of its increasedefficiency it would reduce cash operating costs by $600 per year.  The new machine would require additionalinventories of $700, and accounts receivable would increase by $300. Itsexpected salvage value in 6 years is $2,000.

Thetax rate is 40% and the required rate of return is 13%.  Should the old machine be replaced?

请大神帮忙算算新机器和旧机器各期的现金流量（year0-year6）并详细说明。

另外，请问应收账款和新增存货在现金流量表里应该怎么处理？

如果可以的话，希望能用excel展示详细过程。

万分感激！！！