14 The annual cost of energy in 2021 for each of the 350 households in Village A can be modelled by a random variable \(\pounds X\)
It is given that
$$\sum x = 945000 \quad \sum x ^ { 2 } = 2607500000$$
14
- Calculate the mean of \(X\).
14
- Calculate the standard deviation of \(X\).
14 - For households in Village B the annual cost of energy in 2021 has mean \(\pounds 3100\) and standard deviation £325
Compare the annual cost of energy in 2021 for households in Village A and Village B.