#1.2
import numpy as np
import matplotlib.pyplot as plt
import scipy.stats as stats


x1 = np.arange(-4,4,0.1)
y1 = stats.norm.pdf(x1, 0, 1)
plt.plot(x1, y1, 'gray')

x2 = np.arange(-4,4,0.1)
y2 = stats.norm.pdf(x2, 0, 2)
plt.plot(x2, y2, 'darkorange')

x3 = np.arange(-4,4,0.1)
y3 = stats.norm.pdf(x3, 0, 3)
plt.plot(x3, y3, 'green')

plt.show()