13  Notebook: A Simple Confidence Interval

A small placeholder: the normal approximation for a binomial proportion.

13.1 Wald interval

import math
import pandas as pd

n = 120
k = 58
p_hat = k / n
sigma = math.sqrt(p_hat * (1 - p_hat) / n)
lo = p_hat - 1.96 * sigma
hi = p_hat + 1.96 * sigma

pd.DataFrame({
    "quantity": ["p_hat", "lower bound", "upper bound"],
    "value": [p_hat, lo, hi],
})
quantity value
0 p_hat 0.483333
1 lower bound 0.393922
2 upper bound 0.572745