You can do it with bulk metadata edit/search & replace, using a template as the source.
Here is a capture of the s/r screen.
The template is hard to see in the capture, so here it is
Code:
program: format_number(divide(raw_field('#myfloat'), 1.5), '{0:.2f}')
Change '#myfloat' to the lookup name of your column. The format_number function rounds the result to 2 places (.2f).