Errors and uncertainties (physics)

1. Given that the percentage uncertainty in x is 3% and the percentage uncertainty in y is 5%, what is the percentage uncertainty in z = (x/y)^0.5?

Please guide me in this question, thanks! :)

Δz/z x 100% = Percentage uncertainty in z

(X = power of x, Y = power of y)

Δz/z = X(Δx/x) + Y(Δy/y)

Δz/z = 0.5(3/100) + 0.5(5/100)

Δz/z x 100% = 1.5% + 2.5%

Percentage uncertainity in z = 4%

p/s. i dunno wad and how to delete that block of text above

Mod: Deleted that block :)