Estimator

πœ‡-estimator

For a random sample {𝑋𝑗}𝑛𝑗=1, of identically and independently distributed random variables with mean πœ‡ and variance 𝜎2, the first Sample moment

――𝑋𝑛=𝑀1=1π‘›π‘›βˆ‘π‘—=0𝑋𝑗

estimates the Expectation of the population since

𝔼⁑[――𝑋𝑛]=𝔼⁑[𝑋]Var⁑(――𝑋𝑛)=𝜎2𝑛

This confirms the intuition that the larger a sample, the closer its mean will get to the actual population mean. The distribution of the πœ‡-estimator is described by the Central limits theorem.


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