There is no project preset (project setting) nor export choice for 47.95 frames per second.
The project preset of a project should match the properties of your source media so that the program is directed to establish the correct space in the Edit area monitor space for editing purposes. There is only one project preset for each project. When you have a "mixed Timeline content", you will need to set priorities and then fit everything else into the one setting.
At export, you have opportunities for customizing the export settings under the Advanced Button/Video Tab and Audio Tab. And, what is exported will be as one as definied by the customized export settings.
Can we assume that your "1920 x 1080 @ 47.95 frames per second is progressive and you are in a NTSC setup? If so, look at the project preset
DSLR 1080p30 @ 29.97
Best set manually. For manual project preset setting, please see
Then import your videos into the project.
We can talk about your export intentions next.
Thanks so much! I will try what you recommend and let you know when I am ready to export.