New here, thanks!

Wanted to ask about finding out my percentile in a class (law school). Our school gives out various bins for grades, e.g. 0-50, 50-55, 55-60, 60-64, 64-68,68-72, 72-76, 76-78, 78-80, 80-85, 85-90, 90-100 and tells us how many students fall in each bin, and what percentage of students that is. So, if you got a 76, it would be really easy to know your percentile (just add the total number of students who did as good or better than you divided by total students, or sum the percentiles above you). However, I wanted to try and create a normal curve over my data. I found a tutorial to do it in excel, but that assumes equally sized bins. I also have a histogram of it in R. In an ideal world, I would like to get the equation for my normal curve so that I could solve for my GPA and see my predicted ranking based on normalcy.

At first I thought this would be useful for my resumes, but it would probably just come across as stupid. Now it's mostly just personal interest. Any advice??

Thanks!