hi,
this is due to dashboard widget---Instructor Stats
You have to delete it from the Sidebar
refer this:
http://prntscr.com/phalnt
and if you want to adjust this then you have to make some minor changes
it looks weird because of max course limit is lesser that why it takes the whole width
refer:
http://prntscr.com/phao6z
refer:
http://prntscr.com/phaokp
if you want it to like nice then you can increase the max course limit to 10 and then it will look like
this.
let me know the result after applying this.