I need to prove that $$std(x+c) = std(x)$$
I have been trying to use the properties of the mean such as $$mean(x+c) = mean(x) + c$$
I am confused on the following property of the mean, is this statement correct?
$$\sum\limits_{i=1}^{i=N}(x_i - mean(\{x\}))^2 = mean(\{x\}) \\$$
If that is...