Explain How to Use the Empirical Rule to Solve a

Problem

In the United States, birth weights of newborn

babies are approximately normally distributed with

a mean of u = 3,500 g and a standard deviation of

o = 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.

DONE

0.15%

Step-by-step explanation:

The mean is μ = 3500 and the standard deviation is σ = 500.

2500 is 2 standard deviations below the mean, which we can calculate by finding the z-score.

z = (x - μ) / σ

z = (2500 - 3500) / 500

z = - 2

According to the empirical rule, 99.7% of a normal distribution is between - 2 and + 2 standard deviations. Which means 0.3% is outside of that. Since a normal distribution is symmetrical, half of that, or 0.15%, is less than 2 standard deviations.