JavaScript

//if average of an array is whole number
//method 1:
function isAvgWhole(arr) {
	return Number.isInteger(arr.reduce((accum, val) => accum + val) / arr.length) 
}
//method 2:(not working)
function isAvgBowl(arr)
{
	return Number.isInteger(arr.reduce(function(accum,val)
	{
		return (accum+val)/arr.length
	}))
}
console.log(isAvgWhole([1,1,1,1])) //true
console.log(isAvgBowl([1,1,1,1])) //false

function compareTriplets(a, b) {
    for (let i = 0; i < 4; i ++) {
        points=[];
        pointsArray=[];
        if (a[i] > b[i]) {
            points[i]=1;
            pointsArray.push(points[i])
        } 
         if (a[i] === b[i]) {
             points[i]=0;
        } 
        if (b[i] > a[i]) {
            points[i]=1;
            pointsArray.push(points[i])
        }
        return pointsArray;
    }
}

Guys Please help me , How do I link this HTML with Css and Js properly? 

window.onload = () => {
    startSetTimeoutAnimation();
  };
  
  function startSetTimeoutAnimation() {
    const refreshRate = 1000 / 60;
    const maxXPosition = 400;
    let rect = document.getElementById('rect0');
    let speedX = 0.01;
    let positionX = 25;
  
    window.setInterval(() => {
      positionX = positionX + speedX;
      if (positionX > maxXPosition || positionX < 25) {
        speedX = speedX * (-1);
      }
      rect.style.top = positionX + 'px';
    }, refreshRate);
    
  }