): Daily high temperature (the factor you think causes the change). 1. The Simple Linear Model The goal is to find the equation for a straight line:
Your prediction errors are consistent (you aren't way more "off" on hot days than cold days). Normality: The errors follow a bell curve. Why this matters Regression Analysis by Example
(Slope): For every 1-degree increase in temperature, how many more coffees do you sell? ): Daily high temperature (the factor you think