A large-scale national poll taken recently says President Carter and Ronald Reagan are in a dead heat, with independent John B. Anderson trailing the two front-runners.

The poll, conducted April 29 through May 22, said Carter had support of 37 percent of the sample, while Reagan, the all-but-certain Republican nominee, was the choice of 36 percent.

Anderson drew the backing of 19 percent and 9 percent were undecided in the poll conducted for Targeting Systems Inc. of Washington.

The poll, conducted by William Hamilton and Associates, interviewed 6,601 adults nationwide by telephone. The results are based on interviews with 3,875 likely voters, according to information released at a Washington news conference.

A poll based on about 3,900 respondents has a sampling error of about 2 percentage points.

The Hamilton Poll is similar to recent findings in Roper, Gallup and Harris polls.

The Gallup poll found Reagan leading Carter in a two-way race by 3 percentage points -- 45 percent to 42 percent -- and by one point in a three-way race. With three candidates in the race, the poll gave Reagan 36 percent. Carter 35 percent and Anderson, 23 percent.

The Roper Organization, in a poll released Tuesday, showed Reagan has 40 percent of the vote to Carter's 36 percent, with 24 percent undecided. In a three-way race, Reagan has 34 percent to 29 percent for Carter, 20 percent for Anderson and 17 percent undecided.

In the Abc News-Harris Survey, Reagan leads Carter, 51 to 44 percent.