   * @param {Number} x the cumulative distribution function argument
   *
   * @returns {Number} the cumulative distribution function evaluated at x
   */
  cdf(x: number): number {
    return (1.0 + this.erf(this.standardize(x) * Math.SQRT1_2)) / 2.0
  }

  /**
   * Receives a floating-point number x and returns the value of the inverse of cumulative distribution function
   * from a normal distribution with {@link mean} and {@link standardDeviation} evaluated at x.