s10-basic-statistics.js

function processData(input) {
  //Enter your code here
  input = input.split('\n')[1].split(' ').map(Number)

  frequency = []
  input = input.sort((a, b) => {
    if (a === b)
      frequency.push(a)
    return a - b
  })

  let mean = input.reduce((a, b) => a + b) / input.length

  let median = 0
  if (input.length % 2 === 0) { // even
    median = (input[input.length / 2 - 1] + input[input.length / 2]) / 2
  } else { // odd
    median = input[(input.length - 1) / 2]
  }

  let mode = input[0]
  if (frequency.length > 0) {
    mode = frequency.sort((a, b) => {
      let fa = frequency.filter(v => v === a).length
      let fb = frequency.filter(v => v === b).length

      if (fa === fb && a < b) {
        return fa - fb + 1
      }

      return fa - fb
    })
    mode = mode.pop()
  }

  console.log(parseFloat(mean.toFixed(1)) + '\n' + parseFloat(median.toFixed(1)) + '\n' + mode)
}

processData(`10
64630 11735 14216 99233 14470 4978 73429 38120 51135 67060`)