adding median

docs/Utils.js

@@ -0,0 +1,9 @@
+class Utils {
+
+    // adapted from https://www.w3resource.com/javascript-exercises/fundamental/javascript-fundamental-exercise-88.php
+    static median(arr) {
+        const mid = Math.floor(arr.length / 2);
+        const nums = [...arr].sort((a, b) => a - b);
+        return arr.length % 2 !== 0 ? nums[mid] : (nums[mid - 1] + nums[mid]) / 2;
+    }
+}