diff --git a/iis_project/plotting_utils.py b/iis_project/plotting_utils.py
index c00d264..6f54400 100644
--- a/iis_project/plotting_utils.py
+++ b/iis_project/plotting_utils.py
@@ -3,7 +3,12 @@ from typing import Optional
 
 from scipy.stats import norm
 
-SND_QUARTILE: float = 0.674490
+# XXX: может, заменить вызов scipy.stats.norm на аппроксимацию?
+
+SND_QUARTILE: float = (
+    #0.674490
+    norm.ppf(1 - 0.25)
+)
 
 def suggest_iqr_to_range_to_suggest_bins_num(n: int) -> float:
     p = 1 / (n + 1)