Gretchen invests 6200 dollars in a mutual fund on January 1. On March 1, she learns that her fund balance is 3400 dollars, and she then withdraws 1300 dollars. On August 1, her fund balance is 8600 dollars, and she then deposits 1000 dollars. On the following January 1, her fund balance is 7900 dollars. What is Gretchen's dollar-weighted rate of return? (Assume simple interest and months of equal length.)
Answer = percent.