Please include step-by-step explanation and show formulas used. Please use R to solve the problem as appropriate.

A study is conducted to evaluate the analgesic effectiveness of a daily dose of oral methadone in patients with chronic neuropathic pain. The re- searchers used a scale [0,100] with higher number indicating higher pain. Each subject took either 20 mg of methadone or placebo each day for 5 days, with- out knowing which treatment they were taking. The following table gives the mean maximum pain intensity scores for the 5 days for each subject. Do these data provide suicient evidence to indicate tha the maximum pain intensity is lower on days when methadone is taken? Let a = 0.05. lSubject Methadone Placebo