Give an example of a variable in real life which could be modelled by a normal distribution.
The random variable \(X\) is normally distributed with mean \(\mu\) and variance 21.0. Given that \(\mathrm { P } ( X > 10.0 ) = 0.7389\), find the value of \(\mu\).
If 300 observations are taken at random from the distribution in part (ii), estimate how many of these would be greater than 22.0.