goodway,
<!doctype html>
<html lang="ru">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
const limit = 150;
const rnd = limit => () => Math.random() * (limit + 1)|0;
const length = 37;
const createArray = length => Array.from({length}, rnd(limit));
const array = createArray(length);
const filterMax = max => num => num < max;
const filterSplit = n => num => !(num % n);
document.write(JSON.stringify(array, "", 4)+"<br>");
const array50 = array.filter(filterMax(50));
document.write(JSON.stringify(array50, "", 4)+" < 50 <br>");
const array12 = array.filter(filterSplit(12));
document.write(JSON.stringify(array12, "", 4)+" /12 <br>");
const sum = (a, b) => a + b;
const arraySum = array.reduce(sum);
document.write(`${arraySum} totall<br>`);
document.write(`${arraySum}/${length} = ${(arraySum/length).toFixed(2)}`);
</script>
</body>
</html>