Human pregnancies are normally distributed with a mean of 266 days and a standard deviation of 16 days. The shortest 4% of pregnancies result in babies that are considered clinically premature. What number of days of pregnancy or less corresponds to the birth of a premature baby?

Are you calculating the top or bottom 4%? _____

So, which percentage needs to be converted to an area? _____

What is the area that you will look for in the table (four decimal places)? _____

What area will you actually use from the table (four decimal places)? _____

What is the z-score associated with that area (two decimal places)? _____

What is the cutoff number of days that corresponds to the shortest 4% of pregnancies? (round to the nearest whole numbers) _____ days

Are values lower or higher than that value also in the shortest 4%? _____