Respuesta :
Answer:
2.28% of babies born in the United States having a low birth weight.
Step-by-step explanation:
The complete question is: 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.
We are given that 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.
Let X = birth weights of newborn babies
The z-score probability distribution for the normal distribution is given by;
Z = [tex]\frac{X-\mu}{\sigma}[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = population mean = 3,500 g
[tex]\sigma[/tex] = standard deviation = 500 g
So, X ~ N([tex]\mu=3500, \sigma^{2} = 500[/tex])
Now, the percent of babies born in the United States having a low birth weight is given by = P(X < 2500 mg)
P(X < 2500 mg) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{2500-3500}{500}[/tex] ) = P(Z < -2) = 1 - P(Z [tex]\leq[/tex] 2)
= 1 - 0.97725 = 0.02275 or 2.28%
The above probability is calculated by looking at the value of x = 2 in the z table which has an area of 0.97725.
Answer:
The z-score for 2,500 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 2,500 g.
Step-by-step explanation:
did the assignment on edge:)
