text: const MODERN_ACTIVITY = 15;
  const HALF_LIFE_PERIOD = 5730;
  
  module.exports = function dateSample(sampleActivity) {
    let parsedSampleActivity = parseFloat(sampleActivity);
    let validator = (isNaN(parsedSampleActivity)
      || parsedSampleActivity <= 0
      || parsedSampleActivity > MODERN_ACTIVITY
      || typeof sampleActivity !== "string");
    return validator ? false : Math.ceil(Math.log(MODERN_ACTIVITY / parsedSampleActivity) / (0.693 / HALF_LIFE_PERIOD));
  };
  