acss wrote...
Ok that works well but curious as to the decimel usage since how do
you work it if 45 percent or 55 percent?

=E4*0.55 or =E4*(1-0.45) to reduce by 45%

=E4*0.45 or =E4*(1-0.55) to reduce by 55%

Or you could write these as

=E4*55% or =E4*(100%-45%) to reduce by 45%

=E4*45% or =E4*(100%-55%) to reduce by 55%

This is basic arithmetic.