Ladonna began making annual deposits of $1,600 into an account beginning on April 15, 2018, with the goal of making 20 deposits. Beginning at April 15, 2021, she is unable to make the deposit she planned for that time, and also the next three planned deposits. She then makes all remaining deposits at the times she originally planned, but increases the amount of each remaining deposit to $X so that her account balance at the time of her final deposit is the same as it would have been had she been able to make all deposits as she originally planned. The account pays interest at an annual effective rate of 6.0%. What is $X?