Let X be a real-valued random variable with E[X] and E[X²] denoting the mean values of X and X², respectively. The relation which always holds is

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Answer 1

Concept:

E[X] denotes the mean value of ‘X’

E[X²] denotes the mean value of X²

Also, the variance of Random variable ‘X’ is given as:

Var(X) = E(X²) – [E(X)]²

Note: Variance is always non-negative, i.e.

E[X²] – [E(X)]² ≥ 0

∴ E[X²] ≥ (E[X])²