Comments, observations and thoughts from two bloggers on applied statistics, higher education and epidemiology. Joseph is an associate professor. Mark is a professional statistician and former math teacher.
These curvy lines seem a bit misleading to me. Are they some sort of automatic curve interpolation from Excel?
I can't see any good reason for the curves either, so, yeah, this looks like a case of bad graphing options in Excel. You see this a lot in corporate presentations.On a related topic, I don't care for the wording "function of time" here. "By time" or "broken down by time" would be simpler and more accurate.