Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 3: Q. 2.4 (page 149)

In the chapter-opening Case Study (page 141), the Starnes family arrived at Old Faithful after it had erupted. They wondered how long it would be until the next eruption. Here is a scatterplot that plots the interval between consecutive eruptions of Old Faithful against the duration of the previous eruption, for the month prior to their visit.

Are there any outliers?

Short Answer

Expert verified

Yes, there are outliers for the scatter diagram.

Step by step solution

01

Given Information

The scatter plot is:

02

Explanation

There are some outliers at the higher clusters, as shown in the scatterplot. Because the outliers are so close to the data points, the number of outliers isn't as high.

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.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

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

Managing diabetes People with diabetes measure their fasting plasma glucose (FPG; measured in units of milligrams per milliliter) after fasting for at least 8 hours. Another measurement, made at regular medical checkups, is called HbA. This is roughly the percent of red blood cells that have a glucose

molecule attached. It measures average exposure to glucose over a period of several months. The table below gives data on both HbA and FPG for 18 diabetics five months after they had completed a diabetes education class.

(a) Make a scatterplot with HbA as the explanatory variable. There is a positive linear relationship, but it is surprisingly weak.

(b) Subject 15 is an outlier in the y-direction. Subject 18 is an outlier in the x-direction. Find the correlation for all 18 subjects, for all except Subject 15 and

for all except Subject 18 Are either or both of these subjects influential for the correlation? Explain in simple language why r changes in opposite directions when we remove each of these points.

(c) Add three regression lines for predicting FPG from HbA to your scatterplot: for all 18 subjects, for all except Subject 15 and for all except Subject 18

Is either Subject 15 or Subject 18 strongly influential for the least-squares line? Explain in simple language what features of the scatterplot explain the degree of influence.

Does social rejection hurt? We often describe our emotional reaction to social rejection as “pain.” Does social rejection cause activity in areas of the brain that are known to be activated by physical pain? If it does, we really do experience social and physical pain in similar ways. Psychologists first included and then deliberately excluded individuals from a social activity while they measured changes in brain activity. After each activity, the subjects filled out questionnaires that assessed how excluded they felt. The table below shows data for 13subjects.7“Social distress” is measured by each subject’s questionnaire score after exclusion relative to the score after inclusion. (So values greater than 1show the degree of distress caused by exclusion.) “Brain activity” is the change in activity in a region of the brain that is activated by physical pain. (So positive values show more pain.)

Discuss what the data show. Follow the four-step process.

Measurements on young children in Mumbai, India, found this least-squares line for predicting height yfrom the arm span x y⏜=6.4+0.93xMeasurements are in centimeters (cm).

One child in the Mumbai study had a height of 59cmand an arm span60cmThis child’s residual is

(a)−3.2cm.(c)−1.3cm.(e)62.2cm.(b)−2.2cm.(d)3.2cm.

An eccentric professor believes that a child with an IQ 100should have a reading test score 50and that the reading score should increase by 1 a point for every additional point of IQ. What is the equation of the professor’s regression line for predicting reading scores from IQ?

Least-squares idea The table below gives a small set of data. Which of the following two lines fits the data better: y^=1−xory^=3−2x? Make a graph of the data and use it to help justify your answer. (Note: Neither of these two lines is the least-squares regression line for these data.)
See all solutions

Recommended explanations on Math Textbooks

Applied Mathematics

Read Explanation

Probability and Statistics

Read Explanation

Geometry

Read Explanation

Logic and Functions

Read Explanation

Decision Maths

Read Explanation

Theoretical and Mathematical Physics

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.

Sign-up for free