4 A zoologist is studying the feeding behaviour of a group of 4 gorillas. The random variable \(X\) represents the number of gorillas that are feeding at a randomly chosen moment. The probability distribution of \(X\) is shown in the table below.
| \(r\) | 0 | 1 | 2 | 3 | 4 |
| \(\mathrm { P } ( X = r )\) | \(p\) | 0.1 | 0.05 | 0.05 | 0.25 |
- Find the value of \(p\).
- Find the expectation and variance of \(X\).
- The zoologist observes the gorillas on two further occasions. Find the probability that there are at least two gorillas feeding on both occasions.