What's the count for obese children and adolescents ranked 48?
CREATE TABLE "prevalence_by_state" (
  "state_and_district_of_columbia" text,
  "obese_adults" text,
  "overweight_incl_obese_adults" text,
  "obese_children_and_adolescents" text,
  "obesity_rank" real
);
SELECT "obese_children_and_adolescents" FROM "prevalence_by_state" WHERE "obesity_rank"=48;