In the United States, birth weights of newborn babies are approximately normally distributed with a mean of μ = 3,500 g and a st
andard deviation of σ = 500 g. What percent of babies born in the United States are classified as having a low birth weight (< 2,500 g)? Explain how you got your answer.
answer:The z-score for 2,500 g is –2.
According to the empirical rule, 95% of babies have a birth weight of between 2,500 g and 4,500 g.
5% of babies have a birth weight of less than 2,500 g or greater than 4,500 g.
Normal distributions are symmetric, so 2.5% of babies weigh less than 2,500g.
The z-score for 2,500 g is –2.According to the empirical rule, 95% of babies have a birth weight of between 2,500 g and 4,500 g.5% of babies have a birth weight of less than 2,500 g or greater than 4,500 g.Normal distributions are symmetric, so 2.5% of babies weigh less than 2,500g.
