Page 54, "Cat, Small" section, "4th level Advancement" sub-section: Missing a '+' for the Str bonus
This has been fixed in the errata. It's also fixed in the PRD:
Cat, Small (Cheetah, Leopard)
Starting Statistics: Size Small; Speed 50 ft.; AC +1 natural armor; Attack bite (1d4 plus trip), 2 claws (1d2); Ability Scores Str 12, Dex 21, Con 13, Int 2, Wis 12, Cha 6; Special Qualities low-light vision, scent.
4th-Level Advancement: Size Medium; Attack bite (1d6 plus trip), 2 claws (1d3); Ability Scores Str +4, Dex –2, Con +2; Special Qualities sprint.