1 The amounts of electricity, \(x \mathrm { kWh }\) (kilowatt hours), used by 40 households in a three-month period are summarised as follows. $$n = 40 \quad \sum x = 59972 \quad \sum x ^ { 2 } = 96767028$$

1. Calculate the mean and standard deviation of \(x\).
2. The formula \(y = 0.163 x + 14.5\) gives the cost in pounds of the electricity used by each household. Use your answers to part (i) to deduce the mean and standard deviation of the costs of the electricity used by these 40 households.