1 The random variable \(X\) is normally distributed and is such that the mean \(\mu\) is three times the standard deviation \(\sigma\). It is given that \(\mathrm { P } ( X < 25 ) = 0.648\).
- Find the values of \(\mu\) and \(\sigma\).
- Find the probability that, from 6 random values of \(X\), exactly 4 are greater than 25 .