Questions from Business Statistics

Q: In Exercise 29, we considered whether a linear model would be

In Exercise 29, we considered whether a linear model would be appropriate to describe the trend in the number of passengers departing from the Oakland (CA) airport each month since the start of 1997....

Q: In Chapter 4, we examined Consider the wind speeds in the

In Chapter 4, we examined Consider the wind speeds in the Hopkins Forest over the course of a year. Here the scatterplot we saw then: (Data in Hopkins Forest) 1. Describe the pattern you see here. 2....

Q: As the example in the chapter indicates, one of the important

As the example in the chapter indicates, one of the important factors determining a car Fuel Efficiency is its Weight. Let examine this relationship again, for 11 cars. 1. Describe the association bet...

Q: Now consider the variables igÆ’ and weight in the data set Igf13

Now consider the variables igÆ’ and weight in the data set Igf13. 1. Fit a regression model. If the data violate any assumptions, find a suitable re-expression of igÆ’. 2. Add sex to the model in part...

Q: Hurricane Katrina hurricane force winds extended 120 miles from its center.

Hurricane Katrina hurricane force winds extended 120 miles from its center. Katrina was a big storm, and that affects how we think about the prediction errors. Suppose we add 120 miles to each error t...

Q: In a Chance magazine article (Summer 2005), Danielle Vasilescu and

In a Chance magazine article (Summer 2005), Danielle Vasilescu and Howard Wainer used data from the United Nations Center for Human Settlements to investigate aspects of living conditions for several...

Q: Let try the re-expressed variable Fuel Consumption (gal/

Let try the re-expressed variable Fuel Consumption (gal/100 mi) to examine the fuel efficiency of the 11 cars in Exercise 57. Here are the revised regression analysis and residuals plot: Dependent var...

Q: In Exercise 58 we looked at United Nations data about a country

In Exercise 58 we looked at United Nations data about a country GDP and the average number of people per room (Crowdedness) in housing there. For a re-expression, a student tried the reciprocal 10000|...

Q: The scatterplot shows the gross domestic product (GDP) of the

The scatterplot shows the gross domestic product (GDP) of the United States in trillions of 2009 dollars plotted against years since 1950 A linear model fit to the relationship looks like this: Depend...

Q: Consider again the post-1950 trend in U.S.

Consider again the post-1950 trend in U.S. GDP we examined in Exercise 61. Here are regression output and a residual plot when we use the log of GDP in the model. Is this a better model for GDP? Expla...