text: const MODERN_ACTIVITY = 15;
  const HALF_LIFE_PERIOD = 5730;
  
  module.exports = function dateSample(sampleActivity) {
  
  
      if (typeof sampleActivity !== 'string' || !/^[0-9]*[\.]{0,1}[0-9]*[\.]{0,1}[0-9]*$/.test(sampleActivity)) {
  
          return false;
      }
  
      let num = parseFloat(sampleActivity.match(/^[0-9]*[\.]{0,1}[0-9]*/));
  
      if (num > 0 && num < 15) {
  
          return Math.ceil((Math.log(MODERN_ACTIVITY / num) * HALF_LIFE_PERIOD) / 0.693);
      }
      return false;
  
  
  
  
  
  
  
  };