Time periods of oscillation of the same simple pendulum measured using four different measuring clocks were recorded as $4.62\mathrm{~s}, 4.632\mathrm{~s}, 4.6\mathrm{~s}$ and $4.64\mathrm{~s}$. The arithmetic mean of these readings in correct significant figure is:\\
(1) 5 s\\
(2) 4.623 s\\
(3) 4.6 s\\
(4) 4.62 s