Exact formula is: Initial Size x ( 1 + growth rate)^n where n is the number of periods.
In this case $520m x ( 1+ 0.047)^3 where 3 is the number of years, 520m is the initial market size, and 0.047 is the growth rate.
Since this exact calculation is hard to do without a calculator, you round the 4.7% (or 0.047) to 5.0% (or 0.05), and adjust the formula to the following: $520m ( 1 + 0.05 x 3), or $520 x 1.15, which comes out to $598m. This is just the standard way of making the formula manageable without a calculator, but beware that the more periods you are using this estimate over, the more your answer will be underestimated.
Note that if the market was shrinking instead of growing, you'd just make the growth rate negative.
Hope this helps!