<p>I have an NEC PA241W display. The horizontal resolution is 1,920 pixels (like yours), but my screen measures about 20.5 inches wide. 1,920 / 20.5 = ~93.6585 pixels per inch, so in Photoshop CC2015 my screen resolution is set to 94.</p>
<p>When I view your image in Photoshop at "Print Resolution," it measures about 12 3/16 inches wide by 9 3/16 high on the screen—very close to what you say it's supposed to be.</p>
<p>By the way, while this is an interesting problem, does it really matter for your client, who intends to print the image in a book (on paper I presume)? If the pixel dimensions are right, and it seems yours are, why would the client care what size (or shape) the image appears on your screen?</p>