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The purchased cost of a shell-and-tube heat exchanger (floating-head and carbon-steel tubes) with 10m2 of heating surface was $4200 in 1990 . What will be the 1990 purchased cost of a similar heat exchanger with 20m2 of heating surface if the purchased cost capacity exponent is 0.60 for surface areas ranging from 10 to 40m2 ? If the purchased cost capacity exponent for this type of exchanger is 0.81 for surface areas ranging from 40 to 200m2, what will be the purchased cost of a heat exchanger with 100m2 of heating surface in 2000 ? Marshall and Swift process industry installed equipment index (1990)=929.3 Marshall and Swift provess industry installed equipment index (2000)=1097.7