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If r = 0 and sigma_x, sigma_y are non-zero, then
Abyx = sigma_y / sigma_x
Bbyx = sigma_x
Cbyx = 1
Dbyx = 0 and bxy = 0
Answer & Solution
Correct answer: D. byx = 0 and bxy = 0
1. byx = r * (sigma_y / sigma_x).
2. With r = 0, byx = 0 regardless of sigma's.
3. Similarly bxy = r * (sigma_x / sigma_y) = 0.
4. So both regression coefficients vanish.
_Source: ICAI BoS Foundation Paper 3, Ch 17 'Regression', p.12_
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