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