Measurements of wind speed on a certain island were taken over a period of one year. A box-and-whisker plot of the data obtained is displayed above, and the values of the quartiles are as shown. It is suggested that wind speed can be modelled approximately by a normal distribution with mean \(\mu\) km h\(^{-1}\) and standard deviation \(\sigma\) km h\(^{-1}\).

(i) Estimate the value of \(\mu\).

(ii) Estimate the value of \(\sigma\).