Introduction to Normal Distributions - Assignment

A newborn who weighs 2,500 g or less has a low birth weight. Use the information on the right to find the z-score of a 2,500 g baby.

-2

Brenda is 50 inches tall. Her z-score is

.5

Cynthia's z-score is

0.2

What is the z-score of a newborn who weighs 4,000 g?

1

Approximately % of 7-year-old children are taller than 51 inches.

16

99.7% of all newborn babies in the United States weigh between

2000 and 5000

95% of all newborn babies in the United States weigh between

2500 and 4500

In the United States, birth weights of newborn babies are approximately normally distributed with a mean of ? = 3,500 g and a standard deviation of ? = 500 g. According to the empirical rule, 68% of all newborn babies in the United States weigh between ___ g and ___ g.

3000 and 4000

What weight would give a newborn a z-score of −0.75?

3125

99.7% of 7-year-old children are between inches and inches tall.

43 and 55

95% of 7-year-old children are between inches and inches tall.

45 and 53

Zach has a z-score of -1.5. His height is

46

According to the empirical rule, 68% of 7-year-old children are between inches and inches tall.

47 and 51

Use the information on the right to determine which students will have positive z-scores.

Benjamin, who completed the exam in 86 minutes Cynthia, who completed the exam in 72 minutes

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.

The z-score for 2,500 g 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 2,500g.