(TCO 5) The partnership agreement of Robert and Sal provides that interest at 10% per year is to be credited to each partner on the basis of weighted-average capital balances. A summary of Sal's capital account for the year ended December 31, 20x1 is as follows. Balance, January 1, 20x1 Additional investment, July 1, 20x1 Withdrawal, August 1, 20x1 Balance, December 31, 20x1 Which amount of interest should be credited to Sal's capital account? $140,000 $40,000 ($15,000) $ 165,000 $15,250 O $15,375 O$16,500 O $17,250