Back link for 1 PR

[harsinha0018]

This website has lots of information on this topic:

http://gulati.info/2008/12/importance-links/

[Nizam18]

By that time, the backlink profile for the current top-ranking page will have grown by between +17% and +50%, meaning that it'll now have links from between 64 and 83 referring domains.

[cliftonmor]

There is not specific number or backlinks required
Generally, a ranking of 60 to 100 is phenomenal, 40 to 50 is okay, and below 40 isn't great. If you want to build high-quality backlinks, then start by building links from high domain authority websites that are also relevant to your niche and trusted by searchers all over the Internet.

[ChrisJames661]

PageRank (PR) is a calculation, famously invented by Google founders Larry Page and Sergey Brin, which evaluates the quality and quantity of links to a webpage to determine a relative score of that page's importance and authority on a 0 to 10 scale.