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

Sub into equation

Explanation:

Answer 2

Answer: 2.775%

Explanation:

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

Standard deviation:
`\sigma=500\ g`

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

`z=(x-\mu)/(\sigma)`

For x= 2,500g

`z=(2500-3500)/(500)=(-1000)/(500)=-2`

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

In percent,
`0.02775*100=2.775\%`

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