i did this solution: but only 5/8. what is wrong?

public static int activityNotifications(List expenditure, int d) { int counter=0; int sum=0;

    for(int i=0;i<d;i++){
        sum+=expenditure.get(i);
    }
    for(int i=d; i<expenditure.size();i++){
        double avg=(double)sum/d;
        if(expenditure.get(i)>=2*avg){
            counter++;
        }

        sum-=expenditure.get(i-d);
        sum+=expenditure.get(i);

    }
   return counter;
}