/*! 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} Q 87. The weights of laboratory cockro... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 2: Q 87. (page 143)

The weights of laboratory cockroaches can be modeled with a Normal distribution having mean 80 grams and standard deviation 2 grams. The following figure is the Normal curve for this distribution of weights.

Point C on this Normal curve corresponds to

a.84grams.b.82grams.c.78grams.d.76grams.e.74grams.

Short Answer

Expert verified

The correct option is (b) 82grams

Step by step solution

01

Given information

Population mean (渭)=80

Population standard deviation (s)=2

02

Calculation

Consider X to be a random variable that represents cockroach weight in grams.

The percentage of cockroaches weighing between 76 and 84 grams is computed as follows:

P(76<X<84)=P(76鈭�渭蟽<Z<84鈭�渭蟽)=P(76-802<Z<84-802)=P(鈭�2<Z<2)=0.95

Thus, the required proportion is approximately 95%

Hence, the correct option is(b)

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 91影视!

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

Comparing bone density Refer to Exercise 17 Judy鈥檚 friend Mary also had the bone density in her hip measured using DEXA. Mary is 35 years old. Her bone density is also reported as 948g/cm2 but her standardized score is z=0.50 The mean bone density in the hip for the reference population of 35-year-old women is 944grams/cm2

a. Whose bones are healthier for her age: Judy鈥檚 or Mary鈥檚? Justify your answer.

b. Calculate the standard deviation of the bone density in Mary鈥檚 reference population. How does this compare with your answer to Exercise 17(b)? Are you surprised?

A different species of cockroach has weights that are approximately Normally distributed with a mean of 50 grams. After measuring the weights of many of these cockroaches, a lab assistant reports that 14% of the cockroaches weigh more than 55 grams. Based on this report, what is the approximate standard deviation of weight for this species of cockroaches?

a.4.6b.5.0c.6.2d.14.0

e. Cannot determine without more information.

Batter up! Refer to Exercise 48Use the 68鈥�95鈥�99.7rule to answer the following questions.

a. About what percent of Major League Baseball players with 100 plate appearances had batting averages of 0.363or higher? Show your method clearly.

b. A player with a batting average of 0.227 is at about what percentile in this distribution? Justify your answer.

IQ test scores Scores on the Wechsler Adult Intelligence Scale (an IQ test) for the 20- to 34-year-old age group are approximately Normally distributed with 渭=110 and 蟽=25 .

a. What percent of people aged 20 to 34 have IQs between 125 and 150?

b. MENSA is an elite organization that admits as members people who score in the top 2% on IQ tests. What score on the Wechsler Adult Intelligence Scale would an individual aged 20 to 34 have to earn to qualify for MENSA membership?

Outliers The percent of the observations that are classified as outliers by the 1.5脳IQRrule is the same in any Normal distribution. What is this percent? Show your method clearly.
See all solutions

Recommended explanations on Math Textbooks

Pure Maths

Read Explanation

Calculus

Read Explanation

Mechanics Maths

Read Explanation

Probability and Statistics

Read Explanation

Logic and Functions

Read Explanation

Discrete Mathematics

Read Explanation
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.