I'm attempting to highlight a cell based on two conditions, if the Work Type is equal to (blank), and if the cell itself is greater than 15%, then I want the cell under % Total Work highlighted. My sheet looks like this:

The only way I can think to do this is using the AND function, something like =AND($B:$B="(blank)";$D:$D>.15), but this produces an error. I'm very new to conditional formatting, so I may be missing something obvious. I'm using Excel 2010.