freeCodeCamp/guide/english/certifications/coding-interview-prep/rosetta-code/averages-root-mean-square/index.md

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title: Averages/Root mean square
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# Averages/Root mean square

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## Solutions

<details><summary>Solution 1 (Click to Show/Hide)</summary>

```javascript
function rms(arr) {
  const sumOfSquares = arr.reduce((s, x) => s + x * x, 0);
  return Math.sqrt(sumOfSquares / arr.length);
}
```

</details>