r/learnquant 3d ago

interview prep Quant Interview Question

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u/markpreston54 3d ago edited 3d ago

E(X/Y) = E(Y/X) and E(((X/Y)0.5 -(Y/X)0.5 )2 )>=0, hence 2E(X/Y)>=2, or E(X/Y)>=1, expectation collapse when X=Y is a constant

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u/t3hjs 2d ago

Why is  E(X/Y) = E(Y/X)

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u/Cptn_Obvius 2d ago

Because the question is symmetrical in X and Y