Too many data points when plotting scatter plot, line formatting not showing!

Hi all,

I'm creating an X Y scatter plot with smooth lines, and I'm formatting the line as a dashed line. I have a lot of data points (in hindsight, I recorded way more than I needed during my laboratory test) and the line formatting is not showing up.

Can anyone suggest a fix? Here is a picture http://i.imgur.com/T395KjB.png