9709 P61 - Nov 2009 - Q2
2971
The probability distribution of the random variable \(X\) is shown in the following table.
| \(x\) | -2 | -1 | 0 | 1 | 2 | 3 |
|---|---|---|---|---|---|---|
| \(P(X = x)\) | 0.08 | \(p\) | 0.12 | 0.16 | \(q\) | 0.22 |
The mean of \(X\) is 1.05.
- Write down two equations involving \(p\) and \(q\) and hence find the values of \(p\) and \(q\).
- Find the variance of \(X\).
