(0+0.02+0+0.51)1/2 = 0.74.... How do I get to that answer?

(0+0.02+0+0.51)^1/2 

(0+0.02+0+0.51)^(1/2)=

$${\left({\mathtt{0}}{\mathtt{\,\small\textbf+\,}}{\mathtt{0.02}}{\mathtt{\,\small\textbf+\,}}{\mathtt{0}}{\mathtt{\,\small\textbf+\,}}{\mathtt{0.51}}\right)}^{\left({\frac{{\mathtt{1}}}{{\mathtt{2}}}}\right)} = {\mathtt{0.728\: \!010\: \!988\: \!928\: \!051\: \!8}}$$