If the standard deviation of 11, 13, 15, 17,...., 71 is m, then find the integral part of m.
यदि 11, 13, 15, 17,...., 71 का मानक विचलन (Standard deviation) m है, तो m का समाकल भाग (integral part) ज्ञात कीजिए।
Answer और ExplanationAnswer and explanation
Answer: (C) 17
ये पद एक AP बनाते हैं जिसमें n = 71 − 112 + 1 = 31 और d = 2
AP का प्रसरण (Variance) = (n² − 1)d²12 = 960 × 412 = 320
m = √320 ≈ 17.89
✓
m का पूर्णांक (Integer) भाग 17 है।
The terms form an AP with n = 71 − 112 + 1 = 31 and d = 2
Variance of an AP = (n² − 1)d²12 = 960 × 412 = 320
m = √320 ≈ 17.89
✓
The integral part of m is 17.
Source: RRB NTPC (Graduate) · 25 Mar 2026 · Shift 1। Solution: Prashant Sir, Vijayastra।Source: RRB NTPC (Graduate) · 25 Mar 2026 · Shift 1. Solution by Prashant Sir, from Vijayastra.