=+12.31 ● The article “Mortality Among Recent Purchasers of Handguns” (New England Journal of Medicine [1999]:

1583–1589) examined the relationship between handgun purchases and cause of death. Suppose that a random sample of 4000 death records was examined and cause of death was noted for each individual in the sample. Gun registration records were also examined to determine which of these 4000 individuals had purchased a handgun within the previous year. Data consistent with summary values given in the article are shown in the accompanying table.

Not Suicide Suicide Handgun Purchased 4 12 No Handgun Purchased 63 3921