Suppose a manufacturer of ibuprofen, a common headache remedy, recently developed a new formulation of the drug that is claimed to be more effective. To evaluate the new drug, a sample of 200 current users is asked to try it. After a one month trial, 180 indicated that the new drug was more effective in relieving a headache. At the same time, a sample of 300 current ibuprofen users is given the current drug but told it is the new formulation. From this group, 261 said it was an improvement. At the .05 significance level can we conclude the new drug is more effective?
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