Seven out of 10 Americans rate the quality of higher education in the United States as good or excellent, according to a recent national survey. But a similar number also feel that college costs are beyond the means of the average students.

The survey, conducted this fall by New York-based Group Attitudes Corporation, involved telephone interviews of a random sample of 1299 American adults. Among its conclusions:

* Sixty-eight percent of Americans think collegiate education is good or excellent, and 36 percent believe it is improving. Only one-sixth of the respondents feel it is getting worse.

* Four out of five people surveyed are convinced that college costs will be out of the reach of the average person in the foreseeable future. Nearly seven out of 10 could not afford current college tuition without the aid of loans or grants.

* Six out of 10 Americans feel tuition is too high at public institutions, and seven out of 10 say it is too high at private institutions.

* A large majority of those surveyed support federal aid for students. Ninety percent strongly or somewhat favor federally-funded loans for middle-income students, and 85 percent strongly favor continued federal grants for low-income students. Sixty-three percent think that federal aid for needy college students should be increased.

* Those interviewed also support government funding for academic research: 93 percent are in favor of medical research and 78 percent support research in the physical sciences.

* One-fourth of all Americans intend or hope to complete additional schooling in the future, more than half aiming for a bachelor's degree or higher.