Standard deviation order example

standard-deviation.js

/* Standard Deviation */

const orders = [3, 5, 3, 8, 5, 25, 8, 4]

const arrayAverage = arr => arr.reduce((sum, x) => x + sum, 0) / orders.length

const sumOrders = orders.reduce((sum, x) => x + sum, 0)

const averageOrders = arrayAverage(orders)
console.log(averageOrders)

const differences =
    orders.map(x => x - averageOrders).map(x => x * x)
console.log(differences)

const averageDifference = arrayAverage(differences)
console.log(averageDifference)

const standardDeviation = Math.sqrt(averageDifference)
console.log(standardDeviation)

const isOutlier = orders.map( x => x - averageOrders - standardDeviation > 0)
console.log(isOutlier)