JSFiddle - React, Tailwind, and code Playground

JavaScript

var numbers = [3, 8, 45, 74, 123],
    ratio = 0,
    i = numbers.length;

while ( i-- ) numbers[i] > ratio && ( ratio = numbers[i] );

ratio /= 100;
i = numbers.length;

while (i--) numbers[i] = Math.round( numbers[i] / ratio );

alert(numbers);