5 A random variable \(X\) has the distribution \(\mathrm { B } \left( 5 , \frac { 1 } { 4 } \right)\).
- Find
(a) \(\mathrm { E } ( X )\),
(b) \(\mathrm { P } ( X = 2 )\). - Two values of \(X\) are chosen at random. Find the probability that their sum is less than 2 .
- 10 values of \(X\) are chosen at random. Use an appropriate formula to find the probability that exactly 3 of these values are 2 s .