On Runestone, the text of the problem refers to example 4.2.8. I think this is supposed to refer to example 4.2.4. I guess I'm not exactly sure what the relationship is between the version of the text on Runestone and the version hosted on uleth.ca. (Example 4.2.8 does exist in the Runestone version of the book at the moment, but it's the wrong example; no example 4.2.8 exists in the uleth version of the book right now.)
On Runestone, the text of the problem refers to example 4.2.8. I think this is supposed to refer to example 4.2.4. I guess I'm not exactly sure what the relationship is between the version of the text on Runestone and the version hosted on uleth.ca. (Example 4.2.8 does exist in the Runestone version of the book at the moment, but it's the wrong example; no example 4.2.8 exists in the uleth version of the book right now.)