Code for the Problems in "Probability and Sample Size in Finance"
from math import comb
def probability(choose, num_items):
return comb(num_items, choose) * (0.5)**choose * (1-0.5)**(num_items-choose)
def total_probability(choices, num_items):
print("Num Items", num_items)
value = 0
for choose in choices:
current = probability(choose, num_items)
print(choose, " ", current)
value = value + current
print("Total ", value, "\n")
total_probability(range(0, 5), 10)
total_probability(range(0, 4), 12)
total_probability(range(0, 6), 20)
Output
Num Items 10
0 0.0009765625
1 0.009765625
2 0.0439453125
3 0.1171875
4 0.205078125
Total 0.376953125
Num Items 12
0 0.000244140625
1 0.0029296875
2 0.01611328125
3 0.0537109375
Total 0.072998046875
Num Items 20
0 9.5367431640625e-07
1 1.9073486328125e-05
2 0.0001811981201171875
3 0.001087188720703125
4 0.004620552062988281
5 0.0147857666015625
Total 0.020694732666015625