The arithmetic goes something like this:
Four jump seats in the Cabin. One free regular seat in the Cabin (129 of 130 seats occupied). Three of the Cabin jump seats occupied by attendants for the outbound flight. The unoccupied Cabin jump seat is at the rear of the cabin.
Two jump seats in the cockpit (B737-200).
Positioning crew consists of Captain + First/Officer + three attendants making a total of Five people.
There are four unoccupied seats, two jump seats in the cockpit, one jump seat in the Cabin and one regular seat in the Cabin.
Five into four does not go.
