Population of Town A in 5 years = 39,000(1.05)^5 = 49,775
Population of Town B in 5 years =55,000(0.98)^5 = 49716
which are very close so the Economists are correct.
In ten years after that::-
Town A population will be 49,775(1.05^10 = 81,078
Town B .. .. ... 49,716 * (0.98)^10 = 40,621
Town A is almost double population of Town A. so that prediction is verified.
Whether they will come true or not depends on whether the 5 % growth and/or the 2 % decline will continue through the given time period.