standard deviation in datascience using python matplot lib

import numpy as np
import matplotlib.pyplot as plt

income= np.random.normal(100.0,20.0,10000)

plt.hist(income,50)
plt.show()

output:

income.std()

19.99095786583713

import numpy as np 
import matplotlib.pyplot as plt

income= np.random.normal(100.0,30.0,10000)

plt.hist(income,50)
plt.show()