2 Answers

250,000 x .05 = 12500.00 the first year. 
250,000 + 12,500 = 262,500 x .05 = 13,125 the second year
262,500 + 13,125 = 275625 x .05 = 13781.25 the third year
275625 + 13781.25 = 289406.25 x .05 = 14470.31 the fourth year
289406.25 + 14470.31 = 303876.56 x .05 = 15193.83 the fifth year

303876.56 + 15193.83 = 319070.39 x 05 = 15953.52 the sixth year
319070.39 + 15953.52 = 335023.91 x .05 = 16751.20 the seventh year
335023.91 + 16751.20 = 351775.11 x .05 = 17588.86 the eighth year
351775.11 + 17588.86 = 369363.87 x .05 = 18468.19 the ninth year
369363.87 + 18468.19 = 387832.06 x .05 = 19391.60 the tenth year
$387,832.06 + $19,391.60 = $407,223.66 after ten years

y = ab^x   >  a = 250000,   b = 1,   x = 10

y = 250000(1 + .05)^10

y = 250000(1.05)^10

y = 407,223,65669.......

y = $407,223,66