Chapter 4: Q.4.5 (page 174)

a. Find the regression equation for the data points, use the defining formulas in definition 4.4 to obtain
b. Graph the regression equation and the data points
Short Answer
(a)
(b)

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Chapter 4: Q.4.5 (page 174)

a. Find the regression equation for the data points, use the defining formulas in definition 4.4 to obtain
b. Graph the regression equation and the data points
(a)
(b)

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The coefficient of determination of a set of data points is and the slope of the regression line is . Determine the linear correlation coefficient of the data.
Graduation Rates. Graduation rate-the percentage of entering freshmen attending full time and graduating within 5 years and what influences it is a concern in U.S. colleges and universities.
US News and World Report's "College Guide" provides data on graduation rates for colleges and universities as a function of the per centage of freshmen in the top 10% of their high school class, total spending per student, and student-to-faculty ratio. A random sample of 10 universities gave the following data on student-to-faculty ratio (S/F ratio) and graduation rate (Grad rate).

a. Draw a scatterplot of the data.
b. Is finding a regression line for the data reasonable? Explain your answer.
c. Determine the regression equation for the data, and draw its graph
on the scatterplot you drew in part (a).
d. Describe the apparent relationship between student-to-faculty
ratio and graduation rate.
e. What does the slope of the regression line represent in terms of student-to-faculty ratio and graduation rate?
f. Use the regression equation to predict the graduation rate of a university having a student-to-faculty ratio of 17.
g. Identify outliers and potential influential observations
Corvette Prices. The Kelley Blue Book provides information on wholesale and retail prices of cars. Following are age and price data for 10 randomly selected Corvettes between 1 and 6 years old.
Here, denotes age, in years, and denotes price, in hundreds of dollars. For part (g). predict the prices of a 2 -year-old Corvette and a 3-year-old Corvette.

For which of the following sets of data points can you reasonably determine a regression line? Explain your answer.

Age and Price of Orions. In Table , we provided data on age and price for a sample of Orions between and years old. On the Weiss Stats site, we have given the ages and prices for a sample of Orions between and years old.
a. Obtain a scatterplot for the data.
b. Is it reasonable to find a regression line for the data? Explain your answer.
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