Kalkulator Standar Deviasi

Hitung standar deviasi populasi dan sampel dengan rincian langkah-demi-langkah dan histogram yang menampilkan sebaran data.

σ Distribution & Spread Visualization
σ
Enter your dataset and compute to see the distribution.
📚 Standard Deviation

What is Standard Deviation?

Standard deviation (σ or s) measures the average distance of each data point from the mean. A small standard deviation means data points cluster tightly around the mean; a large one means they're spread out.

σ = √[ Σ(xᵢ − μ)² / N ] (Population)
s = √[ Σ(xᵢ − x̄)² / (n-1) ] (Sample)

The 68-95-99.7 rule (Normal distribution):

  • μ ± 1σ contains ~68% of data
  • μ ± 2σ contains ~95% of data
  • μ ± 3σ contains ~99.7% of data
❓ FAQ

Frequently Asked Questions

Use population (÷N) when you have ALL members of the group. Use sample (÷N-1, Bessel's correction) when your data is a sample and you want to estimate the population's true standard deviation. Sample std dev is always slightly larger.
CV = (σ / μ) × 100%. It expresses standard deviation as a percentage of the mean, allowing comparison of variability across datasets with different units or scales.