''' Variance and standard deviation of a list of numbers ''' def calculate_mean (numbers): s = sum(numbers) N = len(numbers) mean = s/N

return mean

def find_differences(numbers): mean = calculate_mean(numbers)

# Find the differences from the mean
diff =[]
for num in numbers:
    diff.append(num-mean)
return diff

def calculate_variance(numbers):

# Find the list of differences
diff = find_differences(numbers)

# Find the squared differences
squared_diff = []
for d in diff:
    squared_diff.append(d**2) # d를 제곱해서 squared_diff에 저장 
    
# Find the variance
sum_squared_diff = sum(squared_diff)
variance =sum_squared_diff/len(numbers)
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 the numbers is{0}'.format(std))

==================result========== The variance of the list of numbers is 141047.35416666666 The standard deviation of the list of the numbers is375.5627166887931