Bump to v4.0.0.

mean.js

@@ -0,0 +1,21 @@
+define(['./sum'], function(sum) {
+
+  /**
+   * Computes the mean of the values in `array`.
+   *
+   * @static
+   * @memberOf _
+   * @category Math
+   * @param {Array} array The array to iterate over.
+   * @returns {number} Returns the mean.
+   * @example
+   *
+   * _.mean([4, 2, 8, 6]);
+   * // => 5
+   */
+  function mean(array) {
+    return sum(array) / (array ? array.length : 0);
+  }
+
+  return mean;
+});