Beethoven Music Company started business in March 2021. Sales for its first year were $500,000. Beethoven priced its merchandise to yield a 40% gross profit based on sales dollars. Industry statistics suggest that 10% of the merchandise sold to customers will be returned. Beethoven estimated its sales returns based on the industry average. During the year, customers returned $30,000 in sales. Beethoven uses a perpetual inventory system. Prepare summary journal entries to record (1) sales and related COGS, (2) actual sales returns, and (3) the year-end adjusting entry for estimated sales returns. Assume that cash has not yet been collected for merchandise that could yet be returned