at cost	at retail
Beginning inventory	$120	160
Purchases	240	340
Sales	430	-500
Markdowns	60
Markdown cancellations	10
Additional markups	120
Addtional mark up cancellation	20

Using the above data, apply the retail inventory method to compute the approximate average cost (LCM) for the ending inventory. 1. I wonder why there are sales at cost and retail (430, -500) at the same time. I used to solve this type of quiz, but there is always sale at retail. How does sale at cost affect the ending inventory? 2. As far as I know markdown and mark up should be listed at retail line (Right line) not at cost line (left line). If thoses are listed on left line, how does it affect the ending inventory?