"This text is out of sync wi..."

Let's represent a black tongue depressor with a black halo\. We put black halos on 9 out of 10 sick patients and 3 out of 10 healthy patients\. This produces 90% \* 20 = 18 sick patients with black halos \(black tongue depressors\), and 30% \* 80 = 24 healthy patients with black halos\.

This text is out of sync with the graphic -- the pic actually shows black tongue depressors.