math: add mean

math/mean.jule

@@ -0,0 +1,13 @@
+fn Mean(slice: []int): f64 {
+	let l = len(slice)
+	if l == 0 {
+		return 0
+	}
+
+	let mut total: int = 0
+	for _, n in slice {
+		total += n
+	}
+
+	return f64(total) / f64(l)
+}

math/mean_test.jule

@@ -0,0 +1,10 @@
+#build test
+
+use "std/testing"
+
+#test
+fn testMean(t: &testing::T) {
+	t.Assert(Mean([2, 4, 6, 8]) == 5, "mean should be 5")
+	t.Assert(Mean([-3, 0, 3]) == 0, "mean should be 0")
+	t.Assert(Mean([]) == 0, "mean of empty slice should be 0")
+}