Yes I firmly believe that proper backlinks adds to the prospect of having a better Page Rank in Google.And the best way to check for your backlinks is to click on the arrow that is besides your PR bar.It gives you three options a)Related Pages b)Cached Snapshot c)Backlinks.Click on the third options to find out the numbers.
Moreover the PR of any website is based on a simple formula.One could manually calculate it or use a SEO calculator.The formula is as follows.
The Page Rank Of A Website depends solely on your inboud links.The PageRank of a website is calculated with the help of the following equation:
PR(A)=(1-d)+(PR OF LINK PAGE 1*D/NO OF LINKS IN PAGE1)+ (PR OF LINK PAGE 2*D/NO OF LINKS IN PAGE2)+.....+(PR OF LINK PAGE P*D/NO OF LINKS IN PAGE P).
Where A,is your website
D is a damping factor =0.85
link page 1,2...,P are the pages that has a link pointing to your website and can be found out by conducting a search on google with link:www.website.com