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
