Please pardon my questions if they seem silly, as I am in the process of learning 
This is the first time I see "set.seed" function! Based on what I understood from the my websearch- this is done to make sure I get the same P-values every time this code is ran along with my data set?
why set set n=100? is this something to do with normal distribution for the (68-95-99.7)?
Thank you so much for your time!