Finding the Variance and Standard Deviation of a list of numbers in Python
# Finding the Variance and Standard Deviation of a list of numbers
def calculate_mean(n):
s = sum(n)
N = len(n)
# Calculate the mean
mean = s / N
return mean
def find_differences(n):
#Find the mean
mean = calculate_mean(n)
# Find the differences from the mean
diff = []
for num in n:
diff.append(num-mean)
return diff
def calculate_variance(n):
diff = find_differences(n)
squared_diff = []
# Find the squared differences
for d in diff:
squared_diff.append(d**2)
# Find the variance
sum_squared_diff = sum(squared_diff)
variance = sum_squared_diff / len(n)
return variance
if __name__ == '__main__':
donations = [100, 60, 70, 900, 100, 200, 500, 500, 503, 600, 1000, 1200]
variance = calculate_variance(donations)
print('The variance of the list of numbers is {0}'.format(variance))
std = variance ** 0.5
print('The standard deviation of the list of numbers is {0}'.format(std))
#src : Doing Math With Python