The expectation of a random variable X with following distribution :
| X | 0 | 1 | 2 | 3 |
| P(X) | $\frac{1}{6}$ | $\frac{2}{6}$ | $\frac{2}{6}$ | $\frac{1}{6}$ |
is :
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 1.5
The expectation (Mean) of a discrete random variable,
$E(X)=∑X.P(X)$
$=\left(0×\frac{1}{6}\right)+\left(1×\frac{2}{6}\right)+\left(2×\frac{2}{6}\right)+\left(3×\frac{1}{6}\right)$
$=\frac{2+4+3}{6}=\frac{9}{6}=1.5$