JSFiddle - React, Tailwind, and code Playground

HTML

<p>Elementos para os quais quero uma média: 
      <span class="m">2</span>,
      <span class="m">4</span>,
      <span class="m">2</span>,
      <span class="m">3</span>.
</p>
<p>Média pelo ".each()": <b id="r1"></b></p>
<p>Média pelo ".makeArray()": <b id="r2"></b></p>

CSS

.m {color:red}

JavaScript

var tot = 0;
    var n = 0;
    $('.m').each(function(){
       tot += parseInt( $(this).text() );
       n++;
    });
    var MEDIA = tot/n;
    $('#r1').html(MEDIA);


    var A = $.makeArray( $('.m') );
    var Atot = 0;
    for(i=0; i<A.length; i++)
        Atot += parseInt(A[i].innerHTML);
    var Amedia = Atot/A.length;
    $('#r2').html(Amedia);