Question: what is the average size of a baby foot?
Answer: The mean foot length of the 529 babies measured on the first day of life was 7.8 cm (standard deviation 0.4), and the mean foot length of the 182 babies measured on the fifth day was 8.1 cm (SD 0.3). On average, each baby's foot was 0.2 cm (SD 0.3) longer on the fifth day than on the first day.