In London, Ontario, Canada, investigators (Leschied and Cunningham 2002) performed a randomized experiment in which 409 juvenile delinquents were randomly assigned to either multisystemic therapy (MST) or just probation (control group). Of the 211 assigned to therapy, 87 had criminal convictions within 12 months. Of the 198 in the control group, 74 had criminal convictions within 12 months. Determine whether the therapy caused significantly fewer arrests at a 0.05 significance level. Start by comparing the sample percentages.