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 1

Answer:

Sub into equation

Step-by-step explanation:

Answer 2

Answer: 2.775%

Step-by-step explanation:

Given: Mean : $\mu=3,500\ g$

Standard deviation: $\sigma=500\ g$

The formula to calculate z-score is given by :-

$z=\dfrac{x-\mu}{\sigma}$

For x= 2,500g

$z=\dfrac{2500-3500}{500}=\dfrac{-1000}{500}=-2$

The p-value of z = P(z<-2)=0.02275

In percent, $0.02775\times100=2.775\%$

The percent of babies born in the United States are classified as having a low birth weight (< 2,500 g) = 2.775%