//Модуль подключается через uses
type Matrix = array of array of real;
var
A: Matrix;
n, m, i, j, C: byte;
procedure ArithMeanColumn(A: Matrix; C: integer);
var
i: byte;
ArithMean: real;
begin
ArithMean := 0;
for i := 0 to n - 1 do
ArithMean := ArithMean + A[i, C - 1];
ArithMean := ArithMean / C;
writeln(ArithMean:10:3);
end;
begin
write('Введите n: ');
readln(n);
write('Введите m: ');
readln(m);
SetLength(A, n, m);
randomize;
for i := 0 to n - 1 do
begin
for j := 0 to m - 1 do
begin
A[i, j] := random(10);
write(A[i, j]:10:3);
end;
writeln;
end;
write('Введите C: ');
readln(C);
ArithMeanColumn(A, C);
readln;
end.