Pooled estimate of variance

{
  "id": "MLC-T-ENV-021592",
  "term": "Pooled estimate of variance",
  "field": "Environment",
  "definition": "An estimate of precision derived from different sets of duplicates, calculated as follows: S²dp = S²d1 (n₁ - 1) + S²ds (n₂ - 1)/(n₁ - 1) + (n₂ - 1) Where: S²dp = pooled variance; S²d1 = variance observed with the first group of detectors or equipment; S²d2 = variance observed with the second group of detectors or equipment; n₁ = sample size of the first group of detectors or equipment; and n₂ = sample size of the second group of detectors or equipment.",
  "subject": "Air",
  "references": [
    "Radon Glossary of Terms"
  ],
  "url": "https://mlchart.com/terminology/environment/pooled-estimate-of-variance/"
}