Exercise:
A new drug (A) and standard drug (B) were compared in treatment of allergic rhinitis. The drug efficacies were assessed by 4 evaluation grades, significantly effective; effective; no change; or exacerbated. Analyze whether there is statistical difference in drug efficacy between the 2 drugs.
Class 1: Significantly effective, Class 2: Effective, Class 3: No change, Class 4: Exacerbated.