Hi,
What is your output and do the images look okay there? I mean, if you are not giving your customer FM files, it does not matter what the FM screen preview looks like. If you are giving your customer printed files, the printed output matters, so how does that look.
Also, your workflow is suboptimal. Word is not a graphics format and JPEG is a poor choice for those kinds of images. Those kinds of images should be vectors and not rasters, and as vectors would be unaffected by things like resolution.
Instead, find the original artwork, probably EPS, AI, CDR, etc. Import the original artwork by reference into FrameMaker. If you can't find the originals, redraw them as vectors. Lastly, if none of those are options, at least use PNGs, because PNG does not throw data and quality away, like JPEGs do.
I hope this has given you some ideas,
Sean