Two insulation thickness alternatives have been proposed for a process steam line subject to severe weather conditions. One alternative must be selected. Estimated savings in heat loss and installation cost are given below. Which thickness would you recommend for a MARR =15% per year and negligible market (salvage) values? The study period is 12 years. Use the AW method. You may need the following to solve the problem: (A/P,15%,4)=0.3503 \& (A/P,15%,6)=0.2642