Math.swift

import Foundation

struct Math {
    
    static func standardDeviation(values: [Double]) -> Double {
        let squaredAvgDiff = values.map { pow($0 - average(values), 2)}
        let sum = squaredAvgDiff.reduce(0) {$0 + $1}
        return sqrt(sum / Double(values.count))
    }
    
    static func average(values: [Double]) -> Double {
        return values.reduce(0) {$0 + $1} / Double(values.count)
    }
    
}