Taking a class at University. Professor just gave us the CDF for the midterm scores. I have no idea how to read this.
Too afraid to ask in class!

Welcome to devrant, though you could have tried a youtube class/tutoral in the topic
https://youtube.com/watch/...

that's just a snake wiggling it's way to the opposite corner

Let’s take an example and hopefully it helps you understand what it is. Say I want to know what’s the percentage of students that scored less than 50%. From the x-axis, look for 50, look for the point of the graph at 50, and look to it’s y-value. It appears than less than 60% of the class scored less than 50%.

Hope that helps and do ask away so that we may clarify things for you.

Also, it occurs to me that the highest score is below 90, probably at 85 or so. Why? Because the plot reaches 1 before 90, and it looks like it’s around the middle between 80 and 90.

Basically, to describe what a CDF does, it tells you how many things are below every threshold, usually as a percentage.

I conclude that since it's roughly a straight line, all grades are about equally likely. That's weird...