You have probably exported the file to Jpeg. format which is 8 bit file and compressed. So its not the full resolution.
There is also the option to export as a t.ff file 8 bit or 16 bit.
16 bit is the full l resolution and will be even larger than the raw file.
OK, I use to use Photoshop Essentials 14 for the same work and It didn't shrink the MB like it does in LR. And I need the pics to be in JPEG so other people can see them on their phones and computers. So is there anything I can do to change the settings or am i just out of luck.
That is a pretty normal reduction in file size when going from a raw image to a JPEG. Did you set the quality to 100? If those dimensions are the same dimensions as the raw file in Lightroom then you do have a full resolution image. To print an image as large as you are wanting it will probably have a resolution of about 150 PPI. That should be sufficient for an image that size because you won't be standing with your nose against the picture. What are the dimensions of the raw file in Lightroom?
The ORIGINAL RAW dimensions are 5472 x 3648 @ 24.8MB
The unedited JPEG dimensions are 5472 x 3648 @ 10.5 MB after export from LR into a file on my desktop
Those numbers sound reasonable.
Your raw file is 14-bit color or bigger, the JPG is 8-bit, so the max size of the JPG will be about half the size of the raw file.
JPG files use a lossy compression, so the files will be even smaller than half. 90% is an excellent compression setting.
The size of the file is not important for image quality.
The number of pixels (5472 x 3648) is what is important.
DPI/PPI is meaningless for anything other than printing, and even then it is the first number to be discarded and recalculated.
Jeffrey Friedl has a great visual guide to image JPG compression and resulting file size at-
Also a nice explanation by Laura Shoe here-