Which math did Martha Euphemia Lofton Haynes invent?

Martha Euphemia Lofton Haynes did not invent a specific branch of mathematics but made significant contributions to the field of mathematics education and statistical analysis. She was the first African American woman to earn a Ph.D. in mathematics in the United States, in 1933. Haynes focused on improving mathematics curricula and advocated for the inclusion of African American students in advanced math courses. Her work has had a lasting impact on mathematics education, particularly for underrepresented groups.