President Carter's popularity rating, which jumped a record 17 percentage points following the recent Camp David Summit, has declined in the lastest survey but remains 11 points higher than his pre-summit rating.

The lastest survey, based on interviews with 501 people Sept.22-29, shows 50 percent of the public expressing approval of the president's performance in office, while 37 percent disapprove and 13 percent are undecided.

In a survey conducted the day following the president's speech to Congress on the Camp David agreements, 56 percent approved of the way Carter was handling his job, 30 percent disapproved and 14 percent were undecided.

In the presummit survey, just 39 percent expressed approval, 36 percent disapproval and 25 percent were undecided. The Camp David talks clearly drew many of the undecided into the approval column- at least temporarily.

Carter's rating in the weeks ahead will depend on further developments in the Middle East and on the public attitudes and concerns over the economy. For many months the American people have named the twin economis ills of high living costs and unemployment as the top problems facing the nation.

An examination of the four decades of Gallup Poll presidential popularity measurements before and following a dramatic popularity increase shed light on a question now being debated by political observers: How long can Carter's new popularity level be sustained?

Of course, many factors are involved, but history indicates a president's rating dramatically climbs after a particular event and ebbs to the level recorded before the event in about six months' time.

For example, just before the Mayaguez incident in May 1975, President Gerald Ford's popularity stood at 41 percent. After Ford sent troops to rescue the crew of the Mayaguez, his rating jumped to 51 percent approval and then subsequently receded to 39 percent by the end of the year.