The step uses the fractional-exponent rule:

[ a^{m/n}=\sqrt[n]{a^m} ]

So, if the expression is:

[ T_2=365\left(\frac12\right)^{2/3} ]

then

[ \left(\frac12\right)^{2/3} =\sqrt[3]{\left(\frac12\right)^2} =\sqrt[3]{\frac14} =\frac{1}{\sqrt[3]{4}} ]

Therefore,

[ \boxed{T_2=\frac{365}{\sqrt[3]{4}}} ]

Approximately:

[ T_2\approx \frac{365}{1.5874}\approx \boxed{229.9} ]

The written result (\frac{1}{\sqrt[3]{8}}) is not correct for (\left(\frac12\right)^{2/3}). It would involve (\sqrt[3]{4}), not (\sqrt[3]{8}).