For a 95% confidence interval, the corresponding z-score is 1.96. Therefore the deviation will by 1.96*0.5 lbs = 0.98 lbs. Therefore, the confidence interval will be (5 - 0.98, 5 + 0.98), which is (4.02, 5.98). The weight range is from 4.02 lbs to 5.98 lbs.