In devising a test for interviewing engineers for company scholarship, an oil company studied three grades of students to see whether engineering aptitude differed between them. They were also interested in finding out whether there was any difference in the performances of female and male students. Sixty students were used for the test, equally split among the sexes. The grades of students used were

(a) secondary school graduates (SSG),

(b) lower sixth students

(LSS), and

(c) upper sixth students (USS). The students were subjected to two tests

(a) engineering structures aptitude (ESA) and

(b) mathematics aptitude test (MAT). The scores of the students in the study are presented as follows:

Females SSG LSS USS ESA MAT ESA MAT ESA MAT 20 21 28 27 19 19 22222222 24 25 28 29 26 26 3333 29 28 17 26 25 24 22 23 24 3 2 2 3 3 2 2 40 27 40 27 36 29 45 35 32 46 27 32 45 36 29 41 35 36 41 31 33 39 23 27 31 31 40 29 33 33 31 35 25 31 36 33 39 Males SSG LSS USS ESA MAT ESA MAT ESA MAT 20 22 25 40 41 41 22223 24 29 24 28 26 20 333333 23 29 36 40 50 25 27 32 36 53 28 28 41 35 42 24 26 35 38 41 25 24 31 31 46 27 22 29 42 42 24 24 24 26 33 38 37 44 35 36 46 29 24 26 31 31 46