The 16 overhead doors on your loading dock must be replaced now.The deluxe model costs $2,200 each and will last for six years.The standard model costs $1,600 each and will last for four years. The deluxe model is aluminum, so it will have a scrap value of $150 at the end of its life. The standard model is plastic and has no scrap value.The use of the deluxe model on the loading dock will also save your company $1,000 per year in heating costs because of its ability to seal better. If you use an interest rate of 12% and present worth analysis, which door will you recommend? Extend to 12 years to see the present worth analysis in comparison.

What formula do I use to find the extend 12 years to see the present worth analysis in comparison.