Hello, I have a request to provide multiple time period conversion ratios on a single dashboard that can be seen at the same time, in otherwords, not using the user filters. 

I think I have what I need, but when I try to save the formula, I get the below error which really doesn't tell me what might be in error, only that there is one. 

Would anyone be able to help me understand where I am making my mistake please?

(count_if( "Prospects"."Converted Time" = make_duration( 0,0,10,0,0,0))/count_if( "Prospects"."Is Converted?" = selected))*100

Thank you!