The problem is 5-5 part d. As worded is:
"One radar gun used by the Massachusetts Highway Patrol operates at a frequency of 10.525 X 109 cycles/second. By how many cycles/second is the reflected beam shifted in frequency when reflected from a car approaching at 100 kilometers/ hour?"
The book gives the answer 3136, and I can't for the life of me get this answer. I've done this multiple ways and get the same wrong answer every time. Doing similar problems elsewhere I'm getting right answers, so I can only conclude that either I'm overlooking something really, really silly, or there's a typo somewhere in the book. If someone can confirm that 3136 is indeed the right answer, I'll go on trying to figure out where I screwed up.
The link to the full problem is here:
https://phys.libretexts.org/Bookshelves/Relativity/Spacetime_Physics_(Taylor_and_Wheeler)/05%3A_Trekking_through_Spacetime/5.E%3A_Trekking_through_Spacetime_(Exercises)