Initial data commit

Task/Averages-Root-mean-square/JavaScript/averages-root-mean-square-2.js

@@ -0,0 +1,18 @@
+(() => {
+    'use strict';
+
+
+    // rootMeanSquare :: [Num] -> Real
+    const rootMeanSquare = xs =>
+       Math.sqrt(
+            xs.reduce(
+                (a, x) => (a + x * x),
+                0
+           ) / xs.length
+        );
+
+
+    return rootMeanSquare([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
+
+     // -> 6.2048368229954285
+})();