function Test() {
    this.data = { 'a' : 0, 'b' : 6, 'c' : 8, 'd' : 14, 'e' : 11, 'f' : 200, 'aa' : 201, 'www' : 200000 }
}

Test.prototype = {
    StandardDeviation: function (sa) {
        var n = 0;
        var sum = 0;
        for (var key in this.data) {
            n = n + 1;
            sum = sum + Math.pow(( this.data[key] - sa ), 2)
        }
        if (n > 0) {
            return Math.sqrt(sum / n)
        } else {
            return 0
        }
    },
    SimpleAverage: function () {
        var n = 0;
        var sum = 0;
        for (var key in this.data) {
            n = n + 1;
            sum = sum + this.data[key]
        }

        if (n > 0) {
            return sum / n
        } else {
            return 0
        }
    },
    Middle: function (sd, sa) {
        var hash = {};
        for (var key in this.data) {
            if ( this.data[key] <= 3 * sd + sa  && this.data[key] >= sa - 3 * sd )  {
                hash[key] = this.data[key]
            }
        }
        return hash
    },
    run: function () {
        var sa = this.SimpleAverage();
        var sd = this.StandardDeviation(sa);
        console.log(this.Middle(sd, sa));
    }

};

exports.Test = Test;

r = new Test()
r.run()