Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 3: Q 18. (page 173)

More crying? Refer to Exercise 16Does the fact that r=0.45 suggest that making an infant cry will increase his or her IQ later in life? Explain your reasoning.

Short Answer

Expert verified

No.

Step by step solution

01

Given information

02

Explanation

From Exercise 16it is known there exists a weak correlation between the two variables.

The correlation is a statistical measure that is used to explain the relationship between two variables.

The exercise's association reveals a weak relationship between the variables count of crying peaks and an infant's IQat the age of three. Because correlation does not necessarily imply causation.

Thus,

r=0.45does not imply that making an infant cry will lead an increase in her or his IQ in later life.

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

Windy city Is it possible to use temperature to predict wind speed? Here is a scatterplot showing the average temperature (in degrees Fahrenheit) and average wind speed (in miles per hour) for 365 consecutive days at O’Hare International Airport in Chicago.14 Is r>0 or r<0? Closer to r=0orr=±1? Explain your reasoning.

Driving speed and fuel consumption Exercise 9 (page 171) gives data on the fuel consumption y of a car at various speeds x. Fuel consumption is measured in liters of gasoline per 100 kilometers driven, and speed is measured in kilometers per hour. A statistical software package gives the least-squares regression line y^=11.058–0.01466x. Use the residual plot to determine if this linear model is appropriate.

Teaching and research A college newspaper interviews a psychologist about student ratings of the teaching of faculty members. The psychologist says, “The evidence indicates that the correlation between the research productivity and teaching rating of faculty members is close to zero.” The paper reports this as “Professor McDaniel said that good researchers tend to be poor teachers, and vice versa.” Explain why the paper’s report is wrong. Write a statement in plain language (don’t use the word correlation) to explain the psychologist’s meaning.

The stock market Some people think that the behavior of the stock market in January predicts its behavior for the rest of the year. Take the explanatory variable x to be the percent change in a stock market index in January and the response variable y to be the change in the index for the entire year. We expect a positive correlation between x and y because the change during January contributes to the full year’s change. Calculation from data for an 18-year period gives x = X=1.75%sx=5.36%y=9.07%sy=15.35%r=0.596

(a) Find the equation of the least-squares line for predicting full-year change from January change. Show your work.

(b) The mean change in January is x=1.75%. Use your regression line to predict the change in the index in a year in which the index rises1.75% in January. Why could you have given this result (up to roundoff error) without doing the calculation?

Long jumps Here are the 40-yard-dash times (in seconds) and long-jump distances (in inches) for a small class of 12 students:

a. Sketch a scatterplot of the data using dash time as the explanatory variable.

b. Use technology to calculate the equation of the least-squares regression line for predicting the long-jump distance based on the dash time. Add the line to the scatterplot from part (a).

c. Explain why the line calculated in part (b) is called the “least-squares” regression line.
See all solutions

Recommended explanations on Math Textbooks

Logic and Functions

Read Explanation

Probability and Statistics

Read Explanation

Applied Mathematics

Read Explanation

Decision Maths

Read Explanation

Theoretical and Mathematical Physics

Read Explanation

Calculus

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