# 导入统计库
import statistics
# 计算总体方差
print(statistics.pvariance([1, 3, 5, 7, 9, 11]))
print(statistics.pvariance([2, 2.5, 1.25, 3.1, 1.75, 2.8]))
print(statistics.pvariance([-11, 5.5, -3.4, 7.1]))
print(statistics.pvariance([1, 30, 50, 100]))