A four-year review at the Provincial Hospital in Alotau, Papua New Guinea (Barss 1984), found that about 1/40 of their hospital admissions were injuries due to falling coconuts. If coconuts weigh on average 3.2 kg, and the upper bound of the 95% confidence interval is 3.5 kg, what is the lower bound of this confidence interval? Assume a normal distribution of coconut weights.