Purists desist in fitting smooth curves for two reasons: to show the original data points clearly and obviously rather than giving the impression that there are a lot of data points; and because smoothing functions fitted to a limited data set can play up!
why always straight line trend lines??
why not some other trend line- Excel has lots
Purists desist in fitting smooth curves for two reasons: to show the original data points clearly and obviously rather than giving the impression that there are a lot of data points; and because smoothing functions fitted to a limited data set can play up!