* Total Sales for a munufacturing firm;

data sales1;



  date    sales

---------------

 JAN88     236

 FEB88     270

 MAR88     342

 APR88     380

 MAY88     212

 JUN88     461

 JUL88     400

 AUG88     337

 SEP88     379

 OCT88     298

 NOV88     431

 DEC88       .

 JAN89     309

 FEB89     290

 MAR89     416

 APR89     378

 MAY89     501

 JUN89       .

 JUL89     394

 AUG89     423

 SEP89       .

 OCT89     487

 NOV89     519

 DEC89     322

 JAN90       .

 FEB90     453

 MAR90     372

 APR90     430

 MAY90     544

 JUN90     401