Question: In testing to find a cure for congenital heart disease, the condition of a patient after he or she has been treated with a drug cannot be directly quantified, but the patient's condition can be compared with those of other patients with the same illness severity who were treated with other drugs. A pharmaceutical firm conducting clinical trials therefore selects a random sample of 27 patients. The sample is then separated into blocks of three patients each, with the three patients in each block having about the same pretreatment condition. Each person in a block is then randomly assigned to be treated by one of the three drugs under consideration. After the treatment, a physician evaluates each person's condition and ranks the patient in comparison with the others in the same block (with 1 indicating the most improvement and 3 indicating the least improvement). Using the following data, do you believe that all three drugs are equally effective?
