To examine the relationship between alcohol consumption and birth weight, a researcher selects a sample of n = 20 pregnant rats and mixes alcohol with their food for 2 weeks before the pups are born. One newborn pup is randomly selected from each subject's litter and the average birth weight for the n = 20 pups is recorded. It is known that the average birth weight for regular rats (without exposure to alcohol) is α = 5.6 grams.