The Graduate Management Admission Council announced a new campaign Friday to recruit more black students into M.B.A. programs and to help them do well on the GMAT, the admissions test sponsored by the council and used for most M.B.A. programs. The mean score of black students taking the GMAT -- 434 -- is about 100 points lower than the mean for all test takers. The council is starting a series of programs, including the distribution of test preparation materials to historically black colleges and a pledge to those colleges that it will waive fees for any of their student who want to take the test but feel unable to do so for financial reasons.