List the research assistants' full names, capabilities and GPAs who were under the supervision of Merwyn Conkay.
research assistant refers to the student who serves for research where the abbreviation is RA; full names = f_name, l_name;
SELECT T3.f_name, T3.l_name, T2.capability, T3.gpa FROM prof AS T1 INNER JOIN RA AS T2 ON T1.prof_id = T2.prof_id INNER JOIN student AS T3 ON T2.student_id = T3.student_id WHERE T1.first_name = 'Merwyn' AND T1.last_name = 'Conkay'