It could be because you don't pass the totalVotes by reference. So when you calculate totalVotes inside the CalculateTotal function, it only lives inside that function. It doesn't change the value of totalVotes in the main function. Then you try and pass it into the CalculatePercent function. Since it has basically not been initialized to anything. It gives you some garbage as an answer. Try passing it in by reference in the calculateTotal function and see if that changes things for you.
void CalculateTotal(double votes[], double& totalVotes, int arraysize);