Q.4 (A) (iii) |b_xy+b_yx|≥ ____ A. 2|r| B. 2r C. r D. |r|

Answer: (a) 2|r| b_xy and b_yx have the same sign, so |b_xy+b_yx|=|b_xy|+|b_yx|. By A.M. ≥ G.M., frac|b_xy|+|b_yx|2≥sqrtb_xyb_yx=|r|. Hence |b_xy+b_yx|≥ 2|r|.

Chapter: Linear Regression· Mathematics & Statistics (Commerce) Part 2

\(\left|b_{xy}+b_{yx}\right|\ge\) ____

Q.4 (A) (iii) \(\left|b_{xy}+b_{yx}\right|\ge\) ____

A. \(2|r|\)

B. \(2r\)

C. \(r\)

D. \(|r|\)

Doubtly Asked 29 Oct 2026 Board exam · July 2025 hsc 12th Save WhatsApp Report

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Answer: (a) \(2|r|\)

\(b_{xy}\) and \(b_{yx}\) have the same sign, so \(|b_{xy}+b_{yx}|=|b_{xy}|+|b_{yx}|\). By A.M. \(\ge\) G.M., \(\frac{|b_{xy}|+|b_{yx}|}{2}\ge\sqrt{b_{xy}b_{yx}}=|r|\). Hence \(|b_{xy}+b_{yx}|\ge 2|r|\).

Doubtly AI · 29 Oct 2026 AI-verified · Nov 2026 Report

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\(\left|b_{xy}+b_{yx}\right|\ge\) ____

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