running-average

var RunningAverage = require('running-average'); // or use window.RunningAverage in a browser w/out Require.js or Browserify
 
// create an instance
var runningAverage = new RunningAverage();
 
// push a number
runningAverage.push(1);
 
// or a few numbers
runningAverage.push(2, 3, 4);
 
// or an array of numbers
runningAverage.push([5, 6, 7]);
 
// get the current average any time you want
runningAverage.getAverage(); // => 4
 
// add some more numbers
runningAverage.push(8, 9);
 
// get an updated average 
runningAverage.getAverage(); // => 5
 
// oh, and it's chainable too!
runningAverage.push(10).push(11).getAverage(); // => 6