diff --git a/contrib/math/statistics.factor b/contrib/math/statistics.factor
index 2fef5a0834..7b21cd8eaf 100644
--- a/contrib/math/statistics.factor
+++ b/contrib/math/statistics.factor
@@ -2,34 +2,34 @@ IN: math-contrib
 USING: kernel math sequences ;
 
 : mean ( seq -- n )
-	#! arithmetic mean, sum divided by length
+    #! arithmetic mean, sum divided by length
     [ sum ] keep length / ;
 
 : geo-mean ( seq -- n )
-	#! geometric mean, nth root of product
-	[ product ] keep length swap nth-root ;
+    #! geometric mean, nth root of product
+    [ product ] keep length swap nth-root ;
 
 : median ( seq -- n )
-	#! middle number if odd, avg of two middle numbers if even
+    #! middle number if odd, avg of two middle numbers if even
     number-sort dup length dup even? [
-		1+ 2 /i dup 1- rot [ nth ] keep swapd nth + 2 /
-	] [
-		2 / swap nth
-	] if ;
+        1+ 2 /i dup 1- rot [ nth ] keep swapd nth + 2 /
+    ] [
+        2 / swap nth
+    ] if ;
 
 : range ( seq -- n )
-	#! max - min
-	number-sort [ pop ] keep first - ;
+    #! max - min
+    number-sort [ pop ] keep first - ;
 
 : var ( seq -- )
-	#! variance, normalize by N-1
-	dup length 1- dup 0 = [
-		0 2nip
-	] [
-	 	swap [ mean ] keep [ over - sq ] map sum nip swap /
-	] if ;
+    #! variance, normalize by N-1
+    dup length 1- dup 0 = [
+        0 2nip
+    ] [
+        swap [ mean ] keep [ over - sq ] map sum nip swap /
+    ] if ;
 
 : std
-	#! standard deviation, sqrt of variance
-	var sqrt ;
+    #! standard deviation, sqrt of variance
+    var sqrt ;