text: const CustomError = require("../extensions/custom-error");
  
  const MODERN_ACTIVITY= 15; 
  const HALF_LIFE_PERIOD= 5730;
  
  module.exports = function dateSample(sampleActivity) {
    if(typeof sampleActivity !== "string" || isNaN(parseFloat(sampleActivity)) || sampleActivity > MODERN_ACTIVITY || sampleActivity <= 0){
      return false;
    }
  
    return Math.ceil(Math.log(MODERN_ACTIVITY / Number.parseFloat(sampleActivity)) * HALF_LIFE_PERIOD / 0.693 );
  };
  