Answer:
371,000
Step-by-step explanation:
The population will stabilize at a level that has the same number moving in each direction each year. If "b" and "s" represent the numbers of people on the "big" and "small" islands, respectively, we want ...
b + s = 530,000
.03b = .07s
From the second equation, ...
s = (3/7)b . . . . . divide the above equation by .07 and simplify
Substituting this into the first equation, we get ...
b + (3/7)b = 530,000
(10/7)b = 530,000 . . . . collect terms
b = (7/10)(530,000) = 371,000 . . . . . . divide by the coefficient of b
The big island population will stabilize at 371,000 people.