9709 P51 - Jun 2023 - Q6
2974
Eli has four fair 4-sided dice with sides labelled 1, 2, 3, 4. He throws all four dice at the same time. The random variable X denotes the number of 2s obtained.
(a) Show that \(P(X = 3) = \frac{3}{64}\).
(b) Complete the following probability distribution table for \(X\).
| x | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| P(X = x) | \(\frac{81}{256}\) | \(\frac{3}{64}\) | \(\frac{1}{256}\) |
(c) Find \(E(X)\).
