3. Cost $450,000 $690,000 $7,800 Opening inventory Gross purchases RTV Gross sales Markdowns Customer returns Retail $685,000 $1,280,000 $14,000 $987,000 $95,000 $38,000 Utilize the above figures to calculate: a. The closing book inventory at retail. (2 points) b. The cumulative markup% of total merchandise handled. (3 points) c. The cost value of this closing book inventory. (2 points)