Marcel must temporarily invest extra money in his retail business every fall to purchase additional inventory for the Christmas season. On September 1, he already had a total of $57,000 invested in his business. Subsequently, he invested or withdrew cash on various dates as shown. DateAdditional investment or withdrawal October 1$15,000investment November 1$27,000investment February 1$23,000withdrawal March 1$13,000withdrawal May 1$6000withdrawal What was the average cumulative investment in the business during the period from September 1 to August 31? (Assume that each month has the same length.) (Round your answer to the nearest cent.) The (weighted) average investment