The file P$02\_28.$xlsx contains total monthly U$.$S$.$ retail sales data for a number of years. There are really two series, one of actual sales and

possible seasonality, such as higher sales in December and lower sales in February, so that any trends are more apparent.

a$.$ Select a graph of both time series and comment on any observable trends, including a possible seasonal pattern, in the data.

$($i$)$

$($ii$)$

$($iii$)800,000$

$($iv$)800,000$