Answer
$5\%$
Average annual percentage increase: $0.49\%$
Work Step by Step
In 2000, wages were ${$20}$, while in 2010, wages grew to ${$21}$. So the percentage increase in wages is equal to the change over the initial, therefore $\frac{$21 - $20}{$20} = 5\%$.
Let the average annual percentage increase be equal to $x$. We have
$21=20(1+x)^{10}$
$(1+x)^{10}=\frac{21}{20}=1.05.$
$1+x=\sqrt[10]{1.05}\approx 1.0049$
So the approximate average annual percentage change in wages was $0.49\%$.
