uses wincrt;
var i,n:integer;
rata,selisih,varian,sum1,sum2:real;
data:array [1..100] of real;

begin
sum1:=0;
write('banyak data?');readln(n);
writeln('masukkan datanya!');
i:=1;
repeat
write('data ke-',i,' ');
readln(data[i]);
inc(i);
until i>n;
i:=1;
repeat
sum1:=sum1+data[i];
inc(i);
rata:=sum1/n;
until i>n;
i:=1;
repeat
selisih:=sqr(data[i]-rata);
sum2:=sum2+selisih;
inc(i);
varian:=sum2/(n-1);
until i>n;
writeln(varian);
end.

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