This would be the basis of your formula...
Z4=if(isnumber(y4),y4/m4,"")
cb4=if(isnumber(y4),average(z4:ca4))
I also need cb4 to average cells z4-ca4 that contain a %
what else could that range contain?
cb4=if(isnumber(y4),averageif((z4:ca4,"<1",z4:ca4))