text: const MODERN_ACTIVITY= 15; 
  const HALF_LIFE_PERIOD= 5730;
  
  module.exports = function dateSample(sampleActivity) {
    if (typeof sampleActivity !== 'string') {
      return false
    }
    sampleActivity = parseFloat(sampleActivity)
  
    if (sampleActivity > 0 && sampleActivity < MODERN_ACTIVITY) {
      return Math.ceil(Math.log(MODERN_ACTIVITY / sampleActivity) * HALF_LIFE_PERIOD / 0.693);
    }
  
    return false;
  }