The formula for the future value of the account is A = P(1 + r/n)^(nt) where you have A = 19909.20 P = 8975 r = 0.038 t = 21
The resulting equation is not one that can be solved by algebraic means, but we can use a graphing calculator to find n. This graph shows us n = 12, so
0 What is (766*67*89*8*9*87656*7*908786*5*687*78*87*797*87897*8989*089*7654*4*367567*98097987567544*535*567*9*8*6787)0(5*64543534*243467*5*9*7675*643*23*65*878778776546453*53*467*798*89*675*546*32*53*6465*8*76546*34)