diff --git a/acjlecturesday2.org b/acjlecturesday2.org
index 2df9d95..d2eb549 100644
--- a/acjlecturesday2.org
+++ b/acjlecturesday2.org
@@ -240,7 +240,7 @@ Source: [[https://www.nytimes.com/2018/11/02/opinion/the-perversion-of-fiscal-po
 #+end_src
 
 
-*** But in real situations we do not know the population variance!  :slide:
+*** Distribution of sample mean with unknown population variance :slide:
 
 #+RESULTS: sampling5
 [[file:bsample5.png]]