An investor deposits 50 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 15 40 20 June 1 80 80 October 1 175 75 On June 30, the value of the account is 157.50. On December 31, the value of the account is X. Using the time-weighted method, the equivalent annual effective yield during the first 6 months is equal to the (time-weighted) annual effective yield during the entire 1-year period. Calculate X.