JSFiddle - React, Tailwind, and code Playground

JavaScript

temperatures = new Object();

temperatures["monday"] = 23.5;
temperatures["tuesday"] = 22.3;
temperatures["wednesday"] = 28.5;
temperatures["thursday"] = 23.5;
temperatures["friday"] = 22.3;
temperatures["saturday"] = 28.5;
temperatures["sunday"] = 29.5;

var Sum = temperatures["monday"]+temperatures["tuesday"]+temperatures["wednesday"]+temperatures["thursday"]+temperatures["friday"]+temperatures["saturday"]+temperatures["sunday"];

var avg = Sum/7;
document.write(avg);

///OR///
var sum = 0;
for(value in temperatures)
{
    sum  = sum+temperatures[value];
    console.log(temperatures[value]);
}
document.write(sum/7);