Enter the number of people, input fractions, save in the collection, and then read out, to find the average score

Console.Write ("Please enter the number of classes:"); intn =Convert.ToInt32 (Console.ReadLine ()); ArrayList Fenshu=NewArrayList (); Doublesum =0;  for(inti =0; I < n;i++)//to enter the elements of a collection with a For loop{Console.Write ("Please enter section"+ (i+1)+"Personal Score:"); Fenshu. ADD (Double. Parse (Console.ReadLine ()));//cast receive data type is double typeSum + =Double. Parse (Fenshu[i]. ToString ());//casts a collection element to a string type and then casts the string type to a double type            }            foreach(DoubleAinchFenshu)//to output an element in a collection with a traversal array{Console.WriteLine (a); } Console.WriteLine ("the average class score is:"+sum/N); Console.ReadLine ();

Enter the number of people, input fractions, save in the collection, and then read out, to find the average score