It is desired to determine the most economical thickness of insulation for a large cold storage room. Insulation is expected to cost $250 per 1,000 sq. ft of wall area per inch of thickness installed. The insulation is expected to have a useful life of 15 years, at which time it will have to be removed at a cost of $10 per 1,000 sq. ft. of wall area per inch of thickness installed. Annual property taxes and insurance are expected to be 3% of the first cost of the insulation. Heat loss per 1,000 sq.ft. of wall area is a function of insulation thickness. For thicknesses between 3 in. and 8 in., heat loss (measured in Btu/hr) is estimated to equal 4,500(0.82)1-3, where t is the thickness of insulation, measured in inches. Heat loss occurs continuously throughout 365 days/year. The cost of heat removal is estimated at $0.01 per 1,000 Btu, hr. A MARR of 10% applies. Assuming end-of-year costs for annual heat loss, determine the optimum thickness of insulation in the interval [3", 8"], on the basis of insulation being available in in, increments of thickness. Use an EUAC analysis. (10 pts)