E(X-μ) for X and μ Vectors: First Central Moment

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The first central moment E(X-μ) for vectors X and μ, where X follows a normal distribution N(μ, σ²), remains zero. This is because the expectation E(X) equals μ, leading to E(X-μ) being a vector of zeros. Evaluating the expression component-wise confirms that each individual component also results in zero. Thus, even with vector notation, the first central moment retains its property of being zero. The conclusion is that E(X-μ) = [0, 0] for the vector case.
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where X ~ N (μ, σ2)

I know that if X is random variable, the first central moment E(X-E(X)) = E(X-μ) is zero. But I would like to know if X and μ is vector. For example if X = [x1 x2] and μ = [μ1 μ2]. What is the value of E(X-μ)?



Thank you
 
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saintman4 said:
where X ~ N (μ, σ2)

I know that if X is random variable, the first central moment E(X-E(X)) = E(X-μ) is zero. But I would like to know if X and μ is vector. For example if X = [x1 x2] and μ = [μ1 μ2]. What is the value of E(X-μ)?

It's still zero, although now it's a vector of zeros. To see this, simply evaluate it component-wise and apply the scalar result you started with.
 
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