Slope calculation is strictly defined and I don't think that can be simplified than this nevertheless that you are beginner or expert..
You can replicate this calc in Tableau, and if you could attach sample data, we can help to guide.
I'm reading the article thanks. Here is a sample workbook, looking at the trending tab. Just wanting to create a calculation that would allow me to say if it is trending up or trending down via a manual calc.
KPI By Hour Test.twbx 23.3 MB