diff --git a/practica/math/statistic/Variance/Population_variance.py b/practica/math/statistic/Variance/Population_variance.py
new file mode 100644
index 0000000..e314ea6
--- /dev/null
+++ b/practica/math/statistic/Variance/Population_variance.py
@@ -0,0 +1,6 @@
+# дисперсия в генеральной совокупности
+def find_general_variance(x, x_average):
+    variance = 0
+    for i in x:
+        variance += (i - x_average) ** 2
+    return variance / len(x)
diff --git a/practica/math/statistic/Variance/Variance.py b/practica/math/statistic/Variance/Variance.py
new file mode 100644
index 0000000..5d40228
--- /dev/null
+++ b/practica/math/statistic/Variance/Variance.py
@@ -0,0 +1,68 @@
+# ДИСПЕРСИЯ
+# list_data = [int(value) for value in input().split()]
+# n = len(list_data)
+# Sum = 0
+# for value in list_data:
+#     Sum += value
+#     SUm=Sum/n
+# Sum = 0
+# for value in list_data:
+#     a = (value - SUm)**2
+#     Sum += a
+#     D = (Sum / (n - 1 ))
+#     print (D)
+
+# Среднеквадратичное отклонение sd
+# list_data = [int(value) for value in input().split()]
+# n = len(list_data)
+# Sum = 0
+# for value in list_data:
+#     Sum += value
+#     SUm=Sum/n
+# Sum = 0
+# for value in list_data:
+#     a = (value - SUm)**2
+#     Sum += a
+#     D = (Sum / (n - 1 ))
+#     sd = D ** 0.5
+#     print (sd)
+
+
+
+
+    # находим среднее значение
+def find_average(x):
+    return sum(x) / len(x)
+
+
+# находим размах
+def find_range(x):
+    x_copy = sorted(x)
+    return abs(x_copy[-1] - x_copy[0])
+
+# находим медиану
+def find_median(x):
+    if len(x) % 2 == 0:
+        return (x[len(x) // 2] + x[len(x) // 2 -1]) / 2
+    else:
+        return x[len(x) // 2]
+
+# находим дисперсию в генеральной совокупности
+def find_general_variance(x, x_average):
+    variance = 0
+    for i in x:
+        variance += (i - x_average) ** 2
+    return variance / len(x)
+
+
+# находим дисперсию в выборке
+def find_subgeneral_variance(x, x_average):
+    variance = 0
+    for i in x:
+        variance += (i - x_average) ** 2
+    return variance / (len(x) - 1)
+
+
+# возвращаем квадрат из числа
+def get_sqrt(x):
+    return x ** 0.5
\ No newline at end of file
diff --git a/practica/math/statistic/Variance/sample_variance.py b/practica/math/statistic/Variance/sample_variance.py
new file mode 100644
index 0000000..d296f25
--- /dev/null
+++ b/practica/math/statistic/Variance/sample_variance.py
@@ -0,0 +1,6 @@
+# дисперсию в выборке
+def find_subgeneral_variance(x, x_average):
+    variance = 0
+    for i in x:
+        variance += (i - x_average) ** 2
+    return variance / (len(x) - 1)
\ No newline at end of file