Correlation Coefficient

by Ryan Perez

HTML

Population Standard Deviation

JavaScript

var x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var y = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

var sum_x = 0;
var sum_y = 0;
var sum_xy = 0;
var sum_x2 = 0;
var sum_y2 = 0;

for (var i = 0; i < x.length; i++) {
    sum_x += x[i];
    sum_y += y[i];
    sum_xy += x[i] * y[i];
    sum_x2 += x[i] * x[i];
    sum_y2 += y[i] * y[i];
}

var step1 = (10 * sum_xy) - (sum_x * sum_y);
var step2 = (10 * sum_x2) - (sum_x * sum_x);
var step3 = (10 * sum_y2) - (sum_y * sum_y);
var step4 = Math.sqrt(step2 * step3);
var answer = step1 / step4;

console.log(answer);