diff --git a/src/average_median/average_median.c b/src/average_median/average_median.c
index 8b13789..fcb7664 100644
--- a/src/average_median/average_median.c
+++ b/src/average_median/average_median.c
@@ -1 +1,12 @@
+#inlcude "average_median.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
 
+double average(const double *data, int n) {
+    double sum = 0.0;
+    for (int i = 0; i < n; ++i) {
+        sum += data[i];
+    }
+    return sum / n;
+}