Weighted Random number selection

I'm developing a node.js app where a winner has to be randomly selected based on it's win probability in the range of [0, 100] %

My code is as follows:

var activeGame = {
    id: 12324,
    type: 1,
    active: true,
    players: [{
        id: 5032,
        name: "Username",
        foo: true,
        winProbability: 56.32 //%
    }, {
        id: 98243,
        name: "Username",
        foo: true,
        winProbability: 22.68 //%
    }, {
        id: 10943,
        name: "Username",
        foo: false,
        winProbability: 21.00 //%
    }],
};

I've found other algorithms that weren't very clear and didn't work with probabilities adding up to 100%.

I'm looking for a way to create a function selectRandomWinner() to return the index of the winning player but I'm stuck and all and any help would be greatly appreciated. Thanks!