:program trung_binh_cong;
uses crt;
var n , i :interger;
TBC : real;
A:array[1....100]of integer;
begin
writeln('hay nhap do dai cua day so , n :');readln(n);
writeln ('nhap cac phan tu cua day so:');
For i:=1To n do
begin
writeln ('a[',i,']='); readln (a[i]);
end;
tbc:=0;
for i:=1 to n do begin
tbc := a[i]:=(a[i]+i)/n ;
end;
wrriteln ('trung binh cong la ', tbc );
readln
end.