Credit shall be given for purposes of the course of study requirements prescribed by school district governing boards or other authorities having jurisdiction for grades 9 through 12, inclusive, to courses in foreign languages in private schools on the basis of their being at least equivalent to those which would be required for the student in a foreign language class in the same grade level in the public schools. The State Board of Education shall adopt rules and regulations prescribing standards and conditions pursuant to which credit shall be given for those purposes to students in the public schools who have successfully completed foreign language studies in private schools.