Question

In the United States, birth weights of newborn babies are approximately normally distributed with a mean of μ = 3,500 g and a standard 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.

Answer 1

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.

Answer 2

2.5% of babies weigh less than 2,500g.

Empirical rule

Empirical rule states that for a normal distribution, 68% of the values are within 1 standard deviation from the mean, 95% of the values are within 2 standard deviation from the mean and 99.7% are within 3 standard deviation from the mean.

Given that mean (μ) = 3,500 g and a standard deviation of σ = 500 g.

• 95% of babies have a birth weight of between two standard deviation = 2,500 g and 4,500 g

Hence 2.5% of babies weigh less than 2,500g.

Find out more on empirical rule at: https://brainly.com/question/10093236