New car sales for a dealer in Cook County, Illinois, for the past year are shown in the following table, along with monthly indexes $($seasonal relatives$),$ which are supplied to the dealer by the regional distributor.

Month Units Sold Index Month Units Sold Index

Jan. $6460\mathrm{.}70$ Jul. $7640\mathrm{.}90$

Feb. $6560\mathrm{.}80$ Aug. $7841\mathrm{.}10$

Mar. $6410\mathrm{.}60$ Sept. $8141\mathrm{.}20$

Apr. $7410\mathrm{.}94$ Oct. $8141\mathrm{.}20$

May $7460\mathrm{.}89$ Nov. $8241\mathrm{.}20$

Jun. $8431\mathrm{.}00$ Dec. $7841\mathrm{.}25$

Click here for the Excel Data File

a$.$ Deseasonalize car sales. To deseasonalize, take the actual sales for a month, and divide by that month's seasonal index. $($Round your answers to the nearest whole number.$)$

b$.$ The reason we deseasonalize data is to see if we have a trend that was hidden by seasonality. Graph your deseasonalized data from part a using a line graph $($plot January through December on the x axis, and the deseasonalized sales on the y axis$).$ What action might management consider based on what you see in the graph?

multiple choice

Increase inventory because the deasonalized data displays an upward trend

Advertising and sales promotions because the deasonalized data displays a down