CREATE TABLE student (stuid DECIMAL, lname TEXT, fname TEXT, age DECIMAL, sex TEXT, major DECIMAL, advisor DECIMAL, city_code TEXT)
CREATE TABLE has_allergy (stuid DECIMAL, allergy TEXT)
CREATE TABLE allergy_type (allergy TEXT, allergytype TEXT)

Show the average age for male and female students.
SELECT AVG(age), sex FROM student GROUP BY sex
SELECT AVG("age"), "sex" FROM "student" GROUP BY "sex"