Howie's bakery is one of the most popular bakeries in town, and the favorite at Howies's is French bread. Each day of the week, Howie's bakes a number of loaves of French bread, more or less according to a daily schedule. To maintain its fine reputation, Howie's gives away to charity any loaves not sold on the day they are baked. Although this occurs frequently, it is also common for Howie's to run out of French bread on any given day, meaning more demand than supply. In this case, no extra loaves are baked that day. The customers have to go elsewhere (or come back next day) for their French bread. Although French bread at Howie's is always popular, Howie's stimulates demand by running occasional 10% off sales.

Howie's has collected data for 20 weeks, 140 days in all. The variables are Day (Monday-Sunday), Supply (number of loaves baked that day), OnSale (where French bread is on sale), and Demand (loaves actually sold that day). Howie's would like you to see whether regression can be used to estimate the Demand from other data in the file. So that Howies can determine the daily supply in a more cost effective way.