=+41. Motorcycles. More than one million motorcycles are sold annually (www.webbikeworld.com). Off-road motorcycles

(often called “dirt bikes”) are a market segment (about 18%) that is highly specialized and offers great variation in features. This makes it a good segment to study to learn about which features account for the cost (manufacturer’s suggested retail price, MSRP) of a dirt bike. Researchers collected data on 2005 model dirt bikes (lib.stat.cmu.edu/

datasets/dirtbike_aug.csv). Their original goal was to study market differentiation among brands (The Dirt on Bikes: An Illustration of CART Models for Brand Differentiation, Jiang