The previous problems contain time series data. In a time series, data may change as time passes, but why the data is changing is not accounted for in the pattern.Data can follow a pattern:

level or horizontal pattern no change in data values.

trend pattern progressively increasing or decreasing

seasonal pattern regular repeating pattern

Regression can be used to establish a reason for why data is changing.

In this problem, the company believes that the amount they spend on advertising will cause the retail sales to change.

\begin{tabular}{l|l|l|} \hline AutoSave off & Draw \\ \hline \multirow{2}{*}{ Home } & Calibri (Body) \\ \hline \end{tabular} Xa Ch 8 Homework Shell Summer 2017