Published online by Cambridge University Press: 05 June 2012
Overview
Multiple linear regression is a direct extension of simple linear regression. We still use a straight line (linear) function based on ordinary least squares to predict a dependent variable. The only difference here is that multiple (more than one) quantitative or dichotomously coded predictors are used. It is common practice to generate the model (solution) by entering all the variables in a single step; this is sometimes called the standard or simultaneous method. However, other methods that call for entering (or entering and then removing) the variables in stages or steps can be used as well; SAS Enterprise Guide provides several on a drop-down menu that offer a range of method choices. We will focus here on the standard method.
Numerical example
We will use an extension of the example presented in Chapter 16 in which we wished to predict the number of hours that students watched television over 10 weekdays. In addition to grade point average (gpa in the data set) that we used as a variable in Chapters 15 and 16, we will also use the number of pages submitted by the students when they completed their reports (rep_size in the data set), the number of hours the children were in childcare during that 10-day weekday period (childcare hrs in the data set), and the number of hours per week the children used the Internet to interact with the Web site established by the school (internet hrs in the data set) to access school-related assignment and instructor materials.
To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.