File size question (relating to dpi etc)

[Anonymous]

Just getting ready to start some uploads but having a problem with file size. I must be missing a step. When scanning a cover at 600 dpi I get a file about 33M and then after clean up etc I resize to 3246x2160 at 300 dpi and get a file 7.4M. All uploads/catalogs are around 4M for this resolution. I am using an HP scanner with HP S/W to scan, and Photoshop to clean up the image etc. The reduction by a factor of 4 is obviously right, seems like the original file is too big, the quality is great of course. I scanned at 24 bit resolution and scanning at 256 bit doesn't change the file size. Compression is set to 11.

Thanks in advance for your help - hopefully a very simple answer, just can't seem to see the forest for the trees right now.......