A motorist is using the AHP method to choose a new car from three possible models: Arrow, Bestmobile and Commuter. The choice will be based on just two attributes, Cost and Style. The motorist considers that Cost is "moderately more preferred" to Style.

On cost, the Bestmobile is "moderately preferred" to the Arrow, but the Arrow is "moderately preferred" to the Commuter. Also Bestmobile is "extremely preferred" to the Commuter.

On style, the Arrow is "very strongly preferred" to the Bestmobile, but the Comuter is "moderately preferred" to the Arrow, Also, the Commuter is "extremely preferred" to the Bestmobile.

a) Construct the hierarchy to represent the decision problem.

b) Use software, or the approximation method to calculate the weights for each table in the hierarchy and hence determine which car should be purchased.

c) Calculate the inconsistency ratios for the motorist's comparisons of the cars on (i)cost and (ii) style and interpret your results. (use either the software of your choice or the approximation method from the notes)