/*! 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 AP1.6. The figure below shows a Normal ... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Q AP1.6. (page 277)

The figure below shows a Normal density curve. Which of the following gives the best estimates for the mean and standard deviation of this Normal distribution?

(a)渭=200,蟽=50(d)渭=225,蟽=25(b)渭=200,蟽=25(e)渭=225,蟽=275(c)渭=225,蟽=50

Short Answer

Expert verified

The correct option is(c)渭=225,蟽=50

Step by step solution

01

Given information

02

Concept

Observational research looks at people and assesses factors of interest without trying to affect their responses.

03

Calculation

The middle number on the x-axis around which the normal density curve is symmetrical is obtained since the curve is symmetrical about the mean. For this, a perpendicular from the curve's peak is drawn, cutting the x-axis at 225, the mean. 99.7%of the observations fell within this range. The area between 225and 375is 150since the curve is symmetrical.

渭=2253蟽=375鈭�225=150蟽=50

As a result, the best estimates for the normal distribution's mean and standard deviation are:渭=225,蟽=50

As a result, the solution is an option (c).

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

Getting teachers to come to school Elementary schools in rural India are usually small, with a single teacher. The teachers often fail to show up for work. Here is an idea for improving attendance: give the teacher a digital camera with a tamperproof time and date stamp and ask a student to take a photo of the teacher and class at the beginning and end of the day. Offer the teacher better pay for good attendance, verified by the photos. Will this work? Researchers obtained permission to use 120 rural schools in Rajasthan for an experiment to find out.

(a) Explain why it would not be a good idea to offer better pay for good attendance to the teachers in all120schools and then to compare this year鈥檚 attendance with last year鈥檚.

(b) Write a few sentences describing how you would design this experiment.

Do reducing diets work? Dr. Linda Stern and her colleagues recruited 132obese adults at the Philadelphia Veterans Affairs Medical Center in Pennsylvania. Half of the participants were randomly assigned to a low-carbohydrate diet and the other half were assigned to a low-fat diet. Researchers measured each participant鈥檚 change in weight and cholesterol level after six months and again after one year. Subjects in the low-carb diet group lost significantly more weight than subjects in the low-fat diet group during the first six months of the study. At the end of a year, however, the average weight loss for subjects in the two groups was not significantly different.

(a) Why did researchers randomly assign the subjects to the diet treatments?

(b) Explain to someone who knows little statistics what 鈥渓ost significantly more weight鈥� means.

(c) The subjects in the low-carb diet group lost an aver-age of 5.1kg in a year. The subjects in the low-fat diet group lost an average of 3.1kg. Explain how this infor-

mation could be consistent with the fact that weight loss in the two groups was not significantly different.

A simple random sample of 1200 adult Americans is selected, and each person is asked the following question: 鈥淚n light of the huge national deficit, should the government at this time spend additional money to establish a national system of health insurance?鈥� Only 39% of those responding answered 鈥淵es.鈥� This survey

(a) is reasonably accurate since it used a large simple random sample.

(b) needs to be larger since only about 24 people were drawn from each state.

(c) probably understates the percent of people who favor a system of national health insurance.

(d) is very inaccurate but neither understates nor overstates the percent of people who favor a system of national health insurance. Since simple random sampling was used, it is unbiased.

(e) probably overstates the percent of people who favor a system of national health insurance.

Cocoa and blood flowA study conducted by Norman Hollenberg, professor of medicine at Brigham and Women鈥檚 Hospital and Harvard Medical School,

involved 27healthy people aged 18-72. Each subject consumed a cocoa beverage containing 900milligrams of flavonols (a class of flavonoids) daily

for five days. Using a finger cuff, blood flow was measured on the first and fifth days of the study. After five days, researchers measured what they called 鈥渟ignifi-

cant improvement鈥� in blood flow and the function of the cells that line the blood vessels. What flaw in the design of this experiment makes it impossible to say

whether the cocoa really caused the improved blood flow? Explain.

The ABC program Nightline once asked whether the United Nations should continue to have its headquarters in the United States. Viewers were invited to call one telephone number to respond 鈥淵es鈥� and another for 鈥淣o.鈥� There was a charge for calling either number. More than 186,000 callers responded, and 67% said 鈥淣o.鈥�
See all solutions

Recommended explanations on Math Textbooks

Discrete Mathematics

Read Explanation

Calculus

Read Explanation

Statistics

Read Explanation

Geometry

Read Explanation

Mechanics Maths

Read Explanation

Logic and Functions

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.