2016 Update

Task/Averages-Arithmetic-mean/JavaScript/averages-arithmetic-mean-6.js

@@ -0,0 +1,14 @@
+(sample => {
+
+    // mean :: [Num] => (Num | NaN)
+    let mean = lst => {
+        let lng = lst.length;
+
+        return lng ? (
+            lst.reduce((a, b) => a + b, 0) / lng
+        ) : NaN;
+    };
+
+    return mean(sample);
+
+})([1, 2, 3, 4, 5, 6, 7, 8, 9]);

Task/Averages-Arithmetic-mean/JavaScript/averages-arithmetic-mean-7.js

@@ -0,0 +1 @@
+5