text: 
  const MODERN_ACTIVITY= 15; 
  const HALF_LIFE_PERIOD= 5730;
  
  module.exports = function dateSample(sampleActivity ) {
  
    return typeof sampleActivity  === 'string' &&
                Number(sampleActivity) === NaN &&
                    Number(sampleActivity) > 0  ?
     Math.ceil(Math.log(MODERN_ACTIVITY/Number(sampleActivity) )* HALF_LIFE_PERIOD / Math.LN2) : false
  }
   
  