How to use the jstat.jStat.lognormal function in jstat

private generateDouble(): string {
    const number = jStat.lognormal.sample(DOUBLE_LOGNORM_MEAN, DOUBLE_LOGNORM_SIGMA) as number;
    let numberStr = number.toExponential(getRandomInt(20));

    const removeSign = Math.random();
    if (removeSign < 0.1) {
      numberStr = numberStr.replace(/(\+|\-)/gi, '');
    }

    return numberStr;
  }

    return { values: Sample(n, () => jStat.lognormal.sample(mean, stdev)) }
  }

function PERT(min, max, mode = (min + max)/2, lambda = 4) {
  const width = max - min
  const a = 1 + lambda * ((mode - min)/width)
  const b = 1 + lambda * ((max - mode)/width)
  const p = jStat.beta.sample(a, b)
  return min + p*width
}

export const Distributions = {
  beta: jStat.beta.sample,
  centralF: jStat.centralF.sample,
  cauchy: jStat.cauchy.sample,
  chisquare: jStat.chisquare.sample,
  exponential: jStat.exponential.sample,
  invgamma: jStat.invgamma.sample,
  lognormal: jStat.lognormal.sample,
  normal: jStat.normal.sample,
  studentt: jStat.studentt.sample,
  weibull: jStat.weibull.sample,
  uniform: jStat.uniform.sample,
  gamma: jStat.gamma.sample,
  triangular,
  doubleTriangular,
  PERT,
  bernoulli: bernoulli,
  if: bernoulli,
  test: bernoulli,
  binomial: binomial,
  poisson: poisson,
  negBinomial: negBinomial
}

import math from 'mathjs'
import {jStat} from 'jstat'
var Finance = require('financejs')
const finance = new Finance()

const jStatDistributions = {
  beta: jStat.beta.sample,
  centralF: jStat.centralF.sample,
  cauchy: jStat.cauchy.sample,
  chisquare: jStat.chisquare.sample,
  exponential: jStat.exponential.sample,
  invgamma: jStat.invgamma.sample,
  lognormal: jStat.lognormal.sample,
  normal: jStat.normal.sample,
  studentt: jStat.studentt.sample,
  weibull: jStat.weibull.sample,
  uniform: jStat.uniform.sample,
  gamma: jStat.gamma.sample
}

const financeFunctions = {
  PV: finance.PV,
  FV: finance.FV,
  NPV: finance.NPV,
  //IRR: finance.IRR, Too slow.
  PP: finance.PP,
  ROI: finance.ROI,
  AM: finance.AM,
  PI: finance.PI,