2015 YJC P2 Q6

The voltage of a battery is a random variable with the distribution \(\text{N}\hspace{0.1em}\left( \mu ,\ {{\sigma }^{2}} \right)\). The mean voltage of \(4\) randomly selected batteries is denoted by \(\overline{X}\). It is given that \(\text{P}\hspace{0.1em}\left( \overline{X}<22.2 \right)=\text{P}\hspace{0.1em}\left( \overline{X}>26.2 \right)=0.0128\). State the value of \(\mu \) and find the value of \(\sigma \).