Reference no: EM131048348
World record running times. Exercise 28.15 (page 28-31) shows the progress of world record times (in seconds) for the 10,000-meter run for both men and women.
(a) Provide the ANOVA table for the regression model with two regression lines, one for men and one for women.
(b) Are all the individual coefficients significantly different from zero? Set up the appropriate hypotheses, identify the test statistics and P-values, and make conclusions in the context of the problem.
Example 28.15:
If there is a quadratic relationship between a quantitative variable y and another quantitative variable x1, the mean response is given by
A young couple are shopping for a diamond, so they are interested in learning more about how these gems are priced. They have heard about the 4 C's: carat, color, cut, and clarity. Is there is a relationship between these diamond characteristics and the price? Table 28.4 shows records for the first 10 diamonds in a large data base.6 The complete data base contains 351 diamonds and is available in the file DIAMONDS.dat. The variables include Carat, Color, Clarity, the Depth of the cut, the price per carat Price/Ct, and the Total Price. Since the young couple are primarily interested in the price of a diamond, they decide to begin by examining the relationship between Total Price and Carat. Figure 28.11 shows a scatterplot of Total Price versus Carat, along with the estimated quadratic
FIGURE 28.11:
regression model. Using the quadratic regression model, the couple estimate the mean price of a diamond to be
The couple are happy because they can explain 92.6% of the variation in the total price of the diamonds in the data base using this quadratic regression model. However, they are concerned because they used explanatory variables that are not independent. An explanatory variable and its square are obviously related to one another. The correlation between Carat (x1) and Carat2 (x12) is 0.952.
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Created to incorporate this relationship into the model
: Clothing retailer. Since the average purchase amount Purchase12 was such a good predictor, the manager would like you to consider another explanatory variable: the average purchase amount from the previous 12 months. Create the new variable
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Select a policy issue that poses a challenge to governance
: Select a current policy issue (other than the one in the media piece) that poses a challenge to governance and/or public policy. Think about how democracy poses a challenge to resolving the policy issue by means of governance and/or public policy.
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Use statistical software to help you analyze
: Fish sizes. Use explanatory variables length, width, and interaction from Exercise 28.25 (page 28-52) on the 56 perch to provide 95% confidence intervals for the mean and prediction intervals for future observations. Interpret both intervals for t..
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Did you identify a federal or state policy
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Individual coefficients significantly different from zero
: World record running times. Exercise 28.15 (page 28-31) shows the progress of world record times (in seconds) for the 10,000-meter run for both men and women. (a) Provide the ANOVA table for the regression model with two regression lines, one for m..
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Evaluate ulrichs perspective on the fourth wave of hr
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Parepare a presentation to the class that a rock-n-roll song
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Multiple regression model with two explanatory variables
: Fish sizes. Table 28.8 contains data on the size of perch caught in a lake in Finland.10 Use statistical software to help you analyze these data
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Simple linear regression equation for predicting tuition
: Tuition and fees at a small liberal arts college. Information regarding tuition and fees at the University of Virginia from 1970 to 2011 is provided in Table 28.7.9 Use statistical software to answer the following questions. TUITION
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