CBSE 2025 · Region 2 · Set 3 · Q11 · 1 mark
The probability distribution of a random variable X is given by : X -$\displaystyle 4$ -$\displaystyle 3$ -$\displaystyle 2$ -$\displaystyle 1$ $\displaystyle 0$ P(X) $\displaystyle 0.1$ $\displaystyle 0.2$ $\displaystyle 0.3$ $\displaystyle 0.2$ $\displaystyle 0.2$
Then $\displaystyle \mathrm{E}(\mathrm{X})$ of distribution is
| X | -$\displaystyle 4$ | -$\displaystyle 3$ | -$\displaystyle 2$ | -$\displaystyle 1$ | $\displaystyle 0$ |
| P(X) | $\displaystyle 0.1$ | $\displaystyle 0.2$ | $\displaystyle 0.3$ | $\displaystyle 0.2$ | $\displaystyle 0.2$ |
Official answer
From CBSE’s own marking scheme for this paper.
(A)
$\displaystyle -1.8$
ProbabilityMean of a Random VariableApplymcqeasy
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CBSE Class 12 Mathematics past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.