1 The weights, \(x\) grams, of 100 potatoes are summarised as follows.
$$n = 100 \quad \sum x = 24940 \quad \sum x ^ { 2 } = 6240780$$
- Calculate the mean and standard deviation of \(x\).
- The weights, \(y\) grams, of the potatoes after they have been peeled are given by the formula \(y = 0.9 x - 15\). Deduce the mean and standard deviation of the weights of the potatoes after they have been peeled.