3 A sports club has a volleyball team and a hockey team. The heights of the 6 members of the volleyball team are summarised by \(\Sigma x = 1050\) and \(\Sigma x ^ { 2 } = 193700\), where \(x\) is the height of a member in cm . The heights of the 11 members of the hockey team are summarised by \(\Sigma y = 1991\) and \(\Sigma y ^ { 2 } = 366400\), where \(y\) is the height of a member in cm .

1. Find the mean height of all 17 members of the club.
2. Find the standard deviation of the heights of all 17 members of the club.