The Monthly Sales (In Hundreds of Dollars) of a Company

Essay

The monthly sales (in hundreds of dollars) of a company are listed below. $$\begin{array} { | c | c | } \hline \text { Month } & \text { Sales } ( \mathbf { \$ 1 0 0 s } ) \\\hline \text { January } & 12,354 \\\hline \text { February } & 13,657 \\\hline \text { March } & 14,536 \\\hline \text { April } & 13,478 \\\hline \text { May } & 16,590 \\\hline \text { June } & 19,790 \\\hline \text { July } & 17,987 \\\hline \text { August } & 18,657 \\\hline \text { September } & 19,765 \\\hline \text { October } & 18,678 \\\hline \text { November } & 20,678 \\\hline \text { December } & 23,675 \\\hline\end{array}$$
a. Construct a time series plot. What type of pattern exists in the data?
b. Use simple linear regression analysis to find the parameters for the line that minimizes MSE for this time series.
c. What is the sales forecast (in hundreds of dollars) for next month?