nilai mahasiswa

uses wincrt;
var a, siswa : integer;
nilai, total, tinggi, rendah, rata : real;
begin
  total := 0;
  write ('jumlah siswa : '); readln (siswa);
  writeln;
  for a := 1 to siswa do
  begin
    write ('nilai siswa ke ',a,' : '); readln (nilai);
    total := total + nilai;
    if a = 1 then begin
      tinggi := nilai;
      rendah := nilai;
    end
    else begin
      if nilai > tinggi then tinggi := nilai
      else begin
      if nilai < rendah then rendah := nilai;
      end;
    end;
  end;
  rata := total / siswa;
  writeln;
  writeln ('nilai terendah    : ', rendah :1:2);
  writeln ('nilai tertinggi   : ', tinggi :1:2);
  writeln ('rata-rata         : ',rata :1:2);
end.