Cox initially intended to be a deaconess in the Methodist Episcopal Church and did not start her studies at Iowa State College until 1927. By 1933 however she was a faculty member specializing in experimental design. In 1940 she became head of the new Department of Experimental Statistics in the School of Agriculture at North Carolina State College. She was a pioneer in the use of computer programs, with her staff developing many of the early SAS algorithms. She was joint author, with Cochran, of the statistical classic Experimental Designs. In 1956, she was President of the ASA. She was founding Editor of the journal Biometrics in 1945, remaining Editor until 1955. She was President of the IBS in 1968 having been elected an Honorary Life Member in 1964. She was elected to the NAS in 1975.

http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/Cox_Gertrude.pdf Biographical memoir with photograph.