import math


def get_confidence_interval(mean, std_dev, sample_size, ci=1.96):
    """
    Computes the confidence interval assuming a normal distribution of the data
    :param mean: The sample mean
    :param std_dev: The standard deviation (ideally population - otherwise sample std.dev)
    :param sample_size: The number of samples used to estimate mean and std_dev
    :param ci: The z-* multiplier for the desired confidence interval (e.g. 1.96 = 95% CI)
    :return: [lower_bound, upper_bound] of the specified confidence interval
    """
    error_margin = ci * (std_dev / math.sqrt(sample_size))
    return [mean - error_margin, mean + error_margin]