2 For 40 values of the variable \(x\), it is given that \(\Sigma ( x - c ) ^ { 2 } = 3099.2\), where \(c\) is a constant. The standard deviation of these values of \(x\) is 3.2 .
- Find the value of \(\Sigma ( x - c )\).
- Given that \(c = 50\), find the mean of these values of \(x\).