diff --git a/iteration.Rmd b/iteration.Rmd
index 78438dc..36288c1 100644
--- a/iteration.Rmd
+++ b/iteration.Rmd
@@ -130,7 +130,7 @@ That's all there is to the for loop! Now is a good time to practice creating som
     
     x <- sample(100)
     sd <- 0
-    for (i in seq_along(out)) {
+    for (i in seq_along(x)) {
       sd <- sd + (x[i] - mean(x)) ^ 2
     }
     sd <- sqrt(sd) / (length(x) - 1)