/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 90 Babies in the United States have... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Babies in the United States have a mean birth length of \(20.5\) inches with a standard deviation of \(0.90\) inch. The shape of the distribution of birth lengths is approximately Normal. a. Find the birth length at the \(2.5\) th percentile. b. Find the birth length at the \(97.5\) th percentile. c. Find the \(z\) -score for the length at the \(2.5\) th percentile. d. Find the \(z\) -score for the length at the \(97.5\) th percentile.

Short Answer

Expert verified
The birth length at the 2.5th percentile is approximately 18.74 inches and at the 97.5th percentile is approximately 22.26 inches. The Z-score for the length at the 2.5th percentile is -1.96 and at the 97.5th percentile is 1.96.

Step by step solution

01

Find the birth lengths at the given percentiles

To find the birth length at the 2.5th percentile: Use the Z-table to find the Z score that corresponds to the 2.5th percentile which is -1.96. Then, use the formula: Value = Mean + Z(SD), thus, Value = 20.5 + (-1.96 * 0.90). To find the birth length at the 97.5th percentile: Use the Z-table to find the Z score that corresponds to the 97.5th percentile which is 1.96. Then, use the formula: Value = Mean + Z(SD), thus, Value = 20.5 + (1.96 * 0.90)
02

Find Z-scores for the lengths at given percentiles

The Z-score for the length at the 2.5th percentile is -1.96, already given above. Similarly, the Z-score for the length at the 97.5th percentile is 1.96.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

According to National Vital Statistics, the average length of a newborn baby is \(19.5\) inches with a standard deviation of \(0.9\) inch. The distribution of lengths is approximately Normal. Use a table or technology for each question. Include an appropriately labeled and shaded Normal curve for each part. There should be three separate curves. an What is the probability that a baby will have a length of \(20.4\) inches or more? b. What is the probability that a baby will have a length of \(21.4\) inches or more? c. What is the probability that a baby will be between 18 and 21 inches in length?

According to the College Board, the mean quantitative SAT score for male college-bound high school seniors in one year was \(530 .\) SAT scores are approximately Normally distributed with a population standard deviation of \(100 .\) What is the SAT score at the 96 th percentile for male college-bound seniors?

A study of human body temperatures using healthy women showed a mean of \(98.4^{\circ} \mathrm{F}\) and a standard deviation of about \(0.70^{\circ} \mathrm{F}\). Assume the temperatures are approximately Normally distributed. a. Find the percentage of healthy women with temperatures below \(98.6^{\circ} \mathrm{F}\) (this temperature was considered typical for many decades). b. What temperature does a healthy woman have if her temperature is at the 76 th percentile?

The average birth weight of elephants is 230 pounds. Assume that the distribution of birth weights is Normal with a standard deviation of 50 pounds. Find the birth weight of elephants at the 95 th percentile.

The three-year recidivism rate of parolees in Florida is about \(30 \%\); that is, \(30 \%\) of parolees end up back in prison within three years (http://www.floridaperforms.com). Assume that whether one parolee returns to prison is independent of whether any of the others returns. a. Find the probability that exactly 6 out of 20 parolees will end up back in prison within three years, b. Find the probability that 6 or fewer out of 20 parolees will end up back in prison within three years.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.