I needed to install a package called "gee". I got an error. It said I should have had Rtool in my R. I tried to install Rtool, but it gave another error. It was related to my R version because it is an old version (R-3.6.2). I tried to download the new version of R (R-4.0.0). Then I tried to install Rtool, it showed the previous error. It said the current version is R-3.6.2. Now, how can I adjust my R to the new version? Second, after adjusting the new R version, do I need to update Rstudio? In other words, is it necessary to update Rstudio?
Thank you very much.