diff --git a/bootstrap-t.ipynb b/bootstrap-t.ipynb
index 705859d..8f5b40c 100644
--- a/bootstrap-t.ipynb
+++ b/bootstrap-t.ipynb
@@ -46,7 +46,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 84,
+   "execution_count": 86,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -147,7 +147,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 85,
+   "execution_count": 87,
    "metadata": {},
    "outputs": [
     {
@@ -162,34 +162,35 @@
     }
    ],
    "source": [
-    "x = dataset['Female height'].to_numpy()\n",
-    "shapiro_test = stats.shapiro(x)\n",
+    "ALPHA = 0.05\n",
+    "female_heights = dataset['Female height'].to_numpy()\n",
+    "shapiro_test = stats.shapiro(female_heights)\n",
     "\n",
-    "if shapiro_test.pvalue >  0.05:\n",
+    "if shapiro_test.pvalue >  ALPHA:\n",
     "    print(\"Female height: Dane mają rozkład normalny.\")\n",
     "else:\n",
     "    print(\"Female height: Dane nie mają rozkładu normalnego.\")\n",
     "\n",
-    "x = dataset['Male height'].to_numpy()\n",
-    "shapiro_test = stats.shapiro(x)\n",
+    "male_heights = dataset['Male height'].to_numpy()\n",
+    "shapiro_test = stats.shapiro(male_heights)\n",
     "\n",
-    "if shapiro_test.pvalue >  0.05:\n",
+    "if shapiro_test.pvalue >  ALPHA:\n",
     "    print(\"Male height: Dane mają rozkład normalny.\")\n",
     "else:\n",
     "    print(\"Male height: Dane nie mają rozkładu normalnego.\")\n",
     "\n",
-    "x = dataset['Weight before'].to_numpy()\n",
-    "shapiro_test = stats.shapiro(x)\n",
+    "weights_before = dataset['Weight before'].to_numpy()\n",
+    "shapiro_test = stats.shapiro(weights_before)\n",
     "\n",
-    "if shapiro_test.pvalue >  0.05:\n",
+    "if shapiro_test.pvalue >  ALPHA:\n",
     "    print(\"Weight before: Dane mają rozkład normalny.\")\n",
     "else:\n",
     "    print(\"Weight before: Dane nie mają rozkładu normalnego.\")\n",
     "\n",
-    "x = dataset['Weight after'].to_numpy()\n",
-    "shapiro_test = stats.shapiro(x)\n",
+    "weights_after = dataset['Weight after'].to_numpy()\n",
+    "shapiro_test = stats.shapiro(weights_after)\n",
     "\n",
-    "if shapiro_test.pvalue >  0.05:\n",
+    "if shapiro_test.pvalue >  ALPHA:\n",
     "    print(\"Weight after: Dane mają rozkład normalny.\")\n",
     "else:\n",
     "    print(\"Weight after: Dane nie mają rozkładu normalnego.\")\n",