Please help. 1st function works but 2nd which is a re-factor of the 1st does not work? Thanks.

//////// 1. WORKS
function addOne(a) { return a + 1; }

function multiplyByTwo(a, b, c, callback) {
var i, myArr = [];
//console.log(arguments)

for (i = 0; i < 3; i++) {
//console.log(callback(arguments[i] * 2 ))
myArr[i] = callback(arguments[i] * 2);
};
return myArr;
}
console.log(multiplyByTwo(1, 2, 3, addOne))

/////// 2. Does Not WORK
function multiplyByTwo(a, b, c) {
var i, myArr = [];
//console.log(arguments)

for (i = 0; i < 3; i++) {
//console.log(arguments[i] * 2 )
myArr[i] = arguments[i] * 2;
};
return myArr;
}
console.log(multiplyByTwo(1, 2, 3, function (x) {
return x + 1;
}));