Array implement

Hello,
i have to do that :
Write a program to read class grades from a file (A5Q3.dat - which is given to you) into an array grades and to then output to the screen the following information:
Class Average
Percentage of grades >= 90
Percentage of grades < 90 and >= 80
Percentage of grades < 80 and >= 65
Percentage of grades < 65 and >= 50
Percentage of grades < 50
Show average and percentages accurate to 2 places after the decimal (xx.xx and xx.xx%).
I need to put them into functions, but i will do that if i have the correct code, but can't seem to resolve it.
what i was able to do until now is:

Code:

 
int main()
{
    
    int count=0;
    float score[SIZE]={0}, average, scoretotal=0;
    string filename;
    ifstream fin;
    string line;
    float avg;
    
    fin.open("A5Q3.dat");
    
    if (fin.fail())
        cout<<"\nError opening file.\n";
    else
    {
       
        cout<<"============================";
        cout<<endl;
        while ( fin.good() )
        {
          getline (fin,line);          
          cout << line<<endl;
          cout<<endl; 
          
          while(getline(fin,line))
          {                                      
          //or ( int i=0; i<=SIZE;i++){
                int i=0;
                while(fin>>score[i])
                {             
                                    
                              if(score[i]>90)
                        {
                   //   fin>>score[i];
                        count++;
                        avg=score[i]/count;
                        cout<<"Average>90= "<<avg<<endl;
                        }
                        else if(score[i]<90 || score[i]>=80)
                        {
                     // fin>>score[i];
                        count++;
                        avg=score[i]/count;
                        cout<<"Average 80-90"<<avg<<endl;
                        }
                        else if(score[i]<90 || score[i]>=80)
                        {
                   //   fin>>score[i];
                        count++;
                        avg=score[i]/count;
                        cout<<"Average 65-80"<<avg<<endl;
                        }
                        else if(score[i]<90 || score[i]>=80)
                        {
                   //   fin>>score[i];
                        count++;
                        avg=score[i]/count;
                        cout<<"Average 50-65"<<avg<<endl;
                        }
                        else if(score[i]<50)
                        {
                  //    fin>>score[i];
                        count++;
                        avg=score[i]/count;
                        cout<<"Average <50"<<avg<<endl;
                        }
                      else
                      cout<<"Error"<<endl;
                      }  //END IF