Statistics mein dispersion ke measures — mean deviation, variance aur standard deviation — aate hain. Yahan aapko is chapter ke sabse important formulas aur quick revision points free milte hain — NCERT/CBSE syllabus ke hisaab se, boards aur JEE/NEET dono ke liye.
Important Formulas & Concepts — Statistics
- Mean deviation (mean se): Σ|xᵢ − x̄|/n
- Variance σ² = Σ(xᵢ − x̄)²/n
- Alternate: σ² = Σxᵢ²/n − (x̄)²
- Standard deviation σ = √variance
- Grouped data: σ² = Σfᵢ(xᵢ−x̄)²/N
- Step deviation method: σ = h·√[Σfᵢuᵢ²/N − (Σfᵢuᵢ/N)²]
- Coefficient of variation CV = (σ/x̄) × 100
- Comparison: kam CV = zyada consistent
Quick Revision Points
- Variance ki unit squared hoti hai, SD ki original
- Sab observations mein constant add karo to σ same rehta hai
- Constant se multiply karo to σ bhi utne se multiply
- CV se consistency compare hoti hai (cricket averages type questions)
- Table banake systematically solve karo — calculation errors kam honge
📘 Complete Visual Notes + Formula Sheet PDF
Ye sirf ek quick preview hai. Pura chapter — colour-coded mind-maps, saare derivations, solved formula sheet — instant PDF download.
FAQ
Calculation galtiyan kaise bachau?
PDF mein step-deviation ka ready table format hai — usi structure mein solve karo.
CV ka question kaisa hota hai?
Do players/sections compare karne ko denge — kam CV wala consistent.
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