How to link a category to a calculation

I am trying to get the Total Consulting Hours Used and reviewed a few forms but still not getting it to work. Any guidance or assistance would be great! 

var type = @All of Type of Activity;
var hours = @Sum of Hours Completed;
var total = 0;

for(var i = 0; i < hours.length; i++) {
if(type[i].indexOf("Consulting and Technical Assistance") < 0){
total += type[i]
}
};
total