4. An investor deposits 5000 in an investment account on January 1. The following summarizes the activity in the account during the year: Date Value Immediately Before Deposit Deposit March 1 4000 40 June 1 8000 80 September 1 17500 a) Calculate the 9-month time-weighted return it from Jan. 1 to Sept. 1; b) On December 1 the value of the account is X. Using the time-weighted method to calculate X so that the time-weighted annual yield equals the iTW calculated using the 9-month period (similar to #28 of 7.6) 70