= simulatedB simulatedS = simulatedB ## np.random.normal(5, 0.5, size=20) # create 20 fake Beijing prices np.random.normal(5, 0.5, size=10) # create 10 fake Seattle prices , ## array([5.28680292, 5.672704 5.47515532, 4.5042225, 6.10792454, 5.55367062, 5.93738803, 5.53429585, 5.00046181, 4.85310013, 5.49085665, 4.91413966, 5.43145621, 4.6731814 4.76162393, 4.30303043, 5.36229575, 5.64092359, 4.96849 ## ## simulatedS , 4.76309679]) np.mean(simulatedB) - np.mean(simulatedS) ## 0.19683804281616624 Hint: As stated before, the inverse of 10x is log10 x. However, log10 x - log 10 y is NOT equivalent to log10(x y)!