mapValues.js

/**
 * 
 * @param {Number} num 
 * @param {Number} in_min 
 * @param {Number} in_max 
 * @param {Number} out_min 
 * @param {Number} out_max 
 */
mapValues(num, in_min, in_max, out_min, out_max) {
  return (num - in_min) * (out_max - out_min) / (in_max - in_min) + out_min
}

/**
* If we have a scoring range of max 60 min 20, we could do:
*
*/

let scores = [ 60, 40, 36, 32, 30, 20 ]

let max = Math.max(scores)
let min = Math.min(scores)

let mappedScores = scores.forEach(score => {
  return mapValues(score, max, min, 50, 100)
})