Answer:
409600
1990/100, 2000/400, 2010/1,600, 2020/6,400, 2030/25,600
Explanation:
Well I notice there is a pattern... the population multiplies by 4 every 10 years!
With know that, I multiply 25,600 with 4 and multiplied that answer by 4 and got 409600.
I am 100% sure I am right.
Have a gr8 day!