// studentQuery5 is an IEnumerable<string> 
// This query returns those students whose 
// first test score was higher than their 
// average score. 
var studentQuery5 =
    from student in students
    let totalScore = student.Scores[0] + student.Scores[1] +
        student.Scores[2] + student.Scores[3]
    where totalScore / 4 < student.Scores[0]
    select student.Last + " " + student.First;

foreach (string s in studentQuery5)
{
    Console.WriteLine(s);
}

// Output: 
// Omelchenko Svetlana 
// O'Donnell Claire 
// Mortensen Sven 
// Garcia Cesar 
// Fakhouri Fadi 
// Feng Hanying 
// Garcia Hugo 
// Adams Terry 
// Zabokritski Eugene 
// Tucker Michael