(click on picture to make larger)
I'm not the best at explaining this, but I will give it a shot. So here it goes..........
1. Select the Draw an ellipse (circle) shape. It's the second section down on the left.
2. Select Line style window. When you open the window you will have several choices that you can do with the line (right side of screen)
3. When you choose the solid line, you will get a solid outlined circle. If you choose the dashed line (only the one right below the solid line) you will get the dots. Depending on the dashed line you pick will determine how close together your dots will be. (Examples shown)
4. Also in the line style, you can pick thickness. For the solid line, you can slide the thickness bar to make your circle thin or thick. (different thicknesses shown above) For the Dotted line, you will chose the dashed line directly below the solid line. So far I have found that this is the only one that will do the dotted line. For the dashed lines you can choose one of the evenly placed dashes. Moving the thickness bar will make the dashes small or big depending on the thickness you choose. I have also found that you can pick one of the lines that has different size dashes and it will give you the look pictured on the last row above.
You will see quickly the more you play with the different dashed lines and the thickness bar, the different looks you will get. EASY PEASY!!!!
Well I hope this will help you. I only wish I would have figured this out days ago. I searched google for hours trying to figure out how to do this in PSE.