The placebo effect describes the phenomenon of improvement in the condition of a patient taking a placebo-a pill that looks and tastes real but contains no medically active chemicals. Physicians at a clinic in La Jolla, California, gave what they thought were drugs to 7,000 asthma, ulcer, and herpes patients. Although the doctors later learned that the drugs were really placebos, 70% of the patients reported an improved condition. Use this information to test (at α = .05) the placebo effect at the clinic. Assume that if the placebo is ineffective, the probability of a patient's condition improving is .5.