def confidence_interval_dichotomous(
        point_estimate,
        sample_size,
        confidence=.95,
        bias=False,
        percentage=True,
        **kwargs
):
    """Dichotomous confidence interval from sample size and maybe a bias"""
    alpha = ppf((confidence + 1) / 2, sample_size - 1)
    p = point_estimate
    if percentage:
        p /= 100

    margin = sqrt(p * (1 - p) / sample_size)
    if bias:
        margin += .5 / sample_size
    if percentage:
        margin *= 100

    return (point_estimate - alpha * margin, point_estimate + alpha * margin)
Dichotomous confidence interval from sample size and maybe a bias