1 When babies are born, their head circumferences are measured. A random sample of 50 newborn female babies is selected. The sample mean head circumference is 34.711 cm . The sample standard deviation head circumference is 1.530 cm .
- Determine a 95\% confidence interval for the population mean head circumference of newborn female babies.
- Explain why you can calculate this interval even though the distribution of the population of head circumferences of newborn female babies is unknown.