calculate mean, std dev, and std err

labStuff.js

function magic(a) {
    let N = a.length;
    
    let mean = a.reduce((a,b)=>a+b,0) / N;
    
    let sd = 0;
    for (let i=0; i<a.length; i++) {
        sd += ((a[i] - mean) ** 2);
    }
    sd /= N - 1;
    sd = Math.sqrt(sd);

    let sde = sd / Math.sqrt(N);
    
    console.log(`mean: ${mean.toFixed(8)}`);
    console.log(`standard deviation: ${sd.toFixed(8)}`);
    console.log(`standard error: ${sde.toFixed(8)}`);
}

magic([
    1.69, 1.67, 1.69, 1.70, 1.74, 1.70, 1.74, 1.65, 1.79, 1.74
])