Variance Calculator

Inputs

Results update as you type.

Inputs
Spread around the meanSpread around the mean29mean 5myconstructioncalculator.com
Diagram updates as you type.

Results

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Variance (sample)
4.5714
Standard deviation2.1381
Mean5
Count8
Sum of squares Σ(x − mean)²32
Variance (population), for comparison4
Price This optional: add your own prices

Your prices are remembered on this device only.

Working
  1. Mean = 40 ÷ 8 = 5
  2. Squared deviations: (2 − 5)² = 9; (4 − 5)² = 1; (4 − 5)² = 1; (4 − 5)² = 1; (5 − 5)² = 0; (5 − 5)² = 0; (7 − 5)² = 4; (9 − 5)² = 16
  3. Sum of squares = 32
  4. Variance = 32 ÷ (n − 1) = 32 ÷ 7 = 4.5714
  5. Standard deviation = √4.5714 = 2.1381

Results are estimates for planning and material ordering only. They are not a substitute for structural design or approval by a qualified engineer. Read the full disclaimer.

Variance Calculator byMy Construction Calculator: free construction calculators with the working shown.