freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/rosetta-code/averages-root-mean-square.md

id, title, challengeType, forumTopicId, dashedName

id	title	challengeType	forumTopicId	dashedName
594da033de4190850b893874	Averages/Root mean square	5	302228	averagesroot-mean-square

--description--

Compute the Root mean square of the numbers 1 through 10 inclusive.

The root mean square is also known by its initials RMS (or rms), and as the quadratic mean.

The RMS is calculated as the mean of the squares of the numbers, square-rooted:

x\_{\\mathrm{rms}} = \\sqrt {{{x_1}^2 + {x_2}^2 + \\cdots + {x_n}^2} \\over n}.

--hints--

rms should be a function.

assert(typeof rms === 'function');

rms([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) should equal 6.2048368229954285.

assert.equal(rms(arr1), answer1);

--seed--

--after-user-code--

const arr1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const answer1 = 6.2048368229954285;

--seed-contents--

function rms(arr) {

}

--solutions--

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