At time $0,$ Cheryl deposits X into a bank account that credits interest at an annual effective rate of $8\mathrm{.}9\%.$ At time $2,$ Gomer deposits $2800$ into a different bank account that credits simple interest at an annual rate of y$\%.$ At time $7,$ the annual forces of interest on the two accounts are equal, and Gomer's account has accumulated to Z$.$ Calculate Z$.$