In a recent survey, ice cream truck drivers in Cincinnati, Ohio, reported that they make about $280 in income on a typical summer day. The income was generally higher on days with longer work hours, particularly hot days, and on holidays. The accompanying data file includes five weeks of the driver's daily income (Income), number of hours on the road (Hours), whether it was a particularly hot day (Hot = 1 if the high temperature was above 85°F, 0 otherwise), and whether it was a Holiday (Holiday = 1, 0 otherwise).