Python - numpy - mean,sum

import numpy as np

data = np.array([ [40,60,3,3], [60,80,8,11], [80,100,30,41] ])

averages =  data[:,0:2].mean(axis=1)
print('averages:', averages)

multiplications = averages * data[:,2]
print('multiplications:', multiplications)

result = multiplications.sum()
print('result:', result)

# the same in one line

result = (data[:,0:2].mean(axis=1)*data[:,2]).sum()
print('result:', result)

'''
averages: [ 50.  70.  90.]
multiplications: [  150.   560.  2700.]
result: 3410.0
result: 3410.0
'''