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diff --git a/Assignment 2/ex23.py b/Assignment 2/ex23.py
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+# -*- coding: utf-8 -*-
+"""
+Created on Sun Oct 11 18:47:35 2015
+
+@author: Camil Staps (s4498062)
+
+Run with Python 2.7
+"""
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+def all_samples(data, n):
+    """All samples without replacement or ordering with n elements from data"""
+    if n == 0:
+        return [[]]
+    else:
+        samples = []
+        for i, d in enumerate(data):
+            samples = samples + [[d] + s for s in all_samples(data[i+1:], n-1)]
+        return samples
+        
+def nearly_equal(m, n, sig_fig = 5):
+    """Determine whether two numbers are nearly equal"""
+    # http://stackoverflow.com/a/558289/1544337
+    return m == n or int(m * 10 ** sig_fig) == int(n * 10 ** sig_fig)
+
+data = np.array([2,3,6,8,11,18])
+
+# i
+print("Mean: %f\nStandard deviation: %f" % (data.mean(), data.std()))
+    
+samples_2 = all_samples(data, 2)
+samples_4 = all_samples(data, 4)
+
+# ii
+print([(s, np.mean(s)) for s in samples_2])
+print([(s, np.mean(s)) for s in samples_4])
+
+# iii
+samples_2_means = [np.mean(s) for s in samples_2]
+samples_4_means = [np.mean(s) for s in samples_4]
+
+print("Mean of 2-sample means: %f" % np.mean(samples_2_means))
+print("Standard deviation of 2-sample means: %f" % np.std(samples_2_means))
+print("Mean of 4-sample means: %f" % np.mean(samples_4_means))
+print("Standard deviation of 4-sample means: %f" % np.std(samples_4_means))
+
+# iv
+print("Means are equal (2): %r" % (np.mean(samples_2_means) == data.mean()))
+print("Means are equal (4): %r" % (np.mean(samples_4_means) == data.mean()))
+print("σ2 ≈ σ/√2×√(4/5): %r" % nearly_equal(
+        np.std(samples_2_means), data.std() / np.sqrt(2.) * np.sqrt(4./5.)))
+print("σ4 ≈ σ/√4×√(2/5): %r" % nearly_equal(
+        np.std(samples_4_means), data.std() / np.sqrt(4.) * np.sqrt(2./5.)))
+        
+# v
+plt.figure(figsize=(10,4))
+plt.subplot(1, 3, 1)
+plt.hist(data)
+plt.title('Population distribution')
+plt.subplot(1, 3, 2)
+plt.hist(samples_2_means)
+plt.title('2-Sample mean distribution')
+plt.subplot(1, 3, 3)
+plt.hist(samples_4_means)
+plt.title('4-Sample mean distribution')
+plt.show()