title: Statistics at square one. II--Mean from frequency distribution.
mesh_terms: D000367:Age Factors; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007854:Lead / Q000652:urine; D008297:Male; D012737:Sex Factors; D013223:Statistics as Topic
chemical_list: D007854:Lead