Your grandmother gave you $210 for your birthday, which you invested in a mutual fund on January 1, 2012. On June 1, 2012, she gave you $750 for your high school graduation, which you immediately deposited into your mutual fund. On January 1, 2013, found that your dollar-weighted rate of return for the previous year was 7.1%. On April 1, 2013 your fund balance was $1000, and you then deposited $X, which your grandmother gave you for college. On January 1, 2014, your fund balance was $2400, and you calculated that your time weighted rate of return for the previous year was 11.5%. What is X? Note: Assume months of equal length, and assume that simple interest is used to calculate the dollar weighted rate of return.