Chapter 3: Q 32. (page 175)
If women always married men who were 2 years older than themselves, what would be the correlation between the ages of husband and wife?
a. 2
b. 1
c. 0.5
d. 0
e. Can’t tell without seeing the data
The correct option is (b)
Over 30 million students worldwide already upgrade their learning with Vaia!
All the tools & learning materials you need for study success - in one app.
Get started for free
IQ and grades Exercise 3 (page 158) included the plot shown below of school grade point average (GPA) against IQ test score for seventh-grade students. (GPA was recorded on a -point scale with .) Calculation shows that the mean and standard deviation of the IQ scores areand For the GPAs, these values are . The correlation between IQ and GPA is
(a) Find the equation of the least-squares line for predicting GPA from IQ. Show your work.
(b) What percent of the observed variation in these students’ GPAs can be explained by the linear relationship between GPA and IQ?
(c) One student has an IQ of but a very low GPA of . Find and interpret the residual for this student
A school guidance counselor examines how many extracurricular activities students participate in and their grade point average. The guidance counselor says, “The evidence indicates the correlation between the number of extracurricular activities. a student participates in and his or her grade point average is close to 0.” Which of the following is the most appropriate conclusion?
a. Students involved in many extracurricular activities tend to be students with poor grades.
b. Students with good grades tend to be students who are not involved in many extracurricular activities.
c. Students involved in many extracurricular activities are just as likely to get good grades as bad grades.
d. Students with good grades tend to be students who are involved in many
extracurricular activities.
e. No conclusion should be made based on the correlation without looking at a scatterplot of the data.
Actual consumption Refer to Exercise 48. Use the equation of the least-squares regression line and the residual plot to estimate the actual fuel consumption of the car when driving 20 kilometers per hour.
Who’s got hops? Haley, Jeff, and Nathan measured the height (in inches)
and vertical jump (in inches) of 74 students at their school.34 Here is a scatterplot of the data, along with the least-squares regression line. Jacob (highlighted in red) had a vertical jump of nearly 3 feet!
a. Describe the influence that Jacob’s point has on the equation of the least-squares regression line.
b. Describe the influence that Jacob’s point has on the standard deviation of the residuals and r2
More Olympics Athletes who participate in the shot put, discus throw, and hammer throw tend to have different physical characteristics than other track and field athletes. The scatterplot shown here enhances the scatterplot from Exercise by plotting these athletes with blue squares. How are the relationships between height and weight the same for the two groups of athletes? How are the relationships different?
What do you think about this solution?
We value your feedback to improve our textbook solutions.
