36. Many parents have turned to St. John's w ort, a herbal remedy, to treat their children with attention deficit hyperactivity disorder (ADHD). The Journal o f the American Medical Association (June 11, 2008) recently published an article that explored the herb's effectiveness. Children with ADHD were randomly assigned to take e ither St. John's wo r t capsules or placebos. The contingency table below broadly reflects the results found in the study.

Treatment Effect on ADHD No Change in ADHD Improvement in ADHD St. John's wort 12 15 Placebo 14 13 At the 5% significance level, do the data indicate that St. John's w o r t affects children with ADHD?