In the United States, the mean birth weight for boys is 3.41 kg with a standard deviation of 0.55 kg. Assume that the distribution of birth weight is approximately normal. A baby is considered of low birth weight if it weighs less than 2.5 kg. What proportion of baby boys in the United States are born with low birth weight

The proportion of baby boys in the United States that are born with low birth weight is 0.0495.

Step-by-step explanation:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean and standard deviation , the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

3.41 kg with a standard deviation of 0.55 kg.

This means that

What proportion of baby boys in the United States are born with low birth weight?

This is the pvalue of Z when X = 2.5. So

has a pvalue of 0.0495

The proportion of baby boys in the United States that are born with low birth weight is 0.0495.

0.32

step-by-step explanation:

2.24/7