média, moda, mediana

(() => {
  function mode(arr) {
    return arr
      .sort((a, b) => arr.filter(v => v===a).length - arr.filter(v => v===b).length)
      .pop();
  }

  function average(arr) {
    return arr.reduce((carry, item) => carry + item, 0) / arr.length;
  }

  function median(arr) {
    const size = arr.length;

    if (size%2 !== 0)
      return arr[size/2];

    return (arr[size/2] + arr[size/2+1]) / 2;
  }

  const data = prompt('', '').split(' ').map(n => parseFloat(n)).sort((a, b) => a - b);

  console.log('Mediana:', median(data));
  console.log('Média:', average(data));
  console.log('Moda:', mode(data));
})();