I don't think so.

As I understand AdWords policies, placement is determined by bid price AND the specific ad's performance. In other words, the first 1 or 2 or 3 ads could be lower paying than the 4th one. Or they might not, depending on CTR factors for each ad.

thanks for the reply.

also I was wondering is it true that the higher the PR of your website and the more established your site, the higher CPC?

Once again, no. (Where are you getting this info?)

PR is a factor based in link juice, and has little to do with your search ranking, and certainly nothing to do directly with the AdSense business.

The one connection I can see between PR and "established sites" AND CPC would be in that better, stronger sites might be targeted by ADWords advertisers who are choosing the specific sites they wish to be on. If those advertisers happened to have higher AdWords bids, then there would be a lifting effect on your overall eCPM. But there is nothing to prevent a low-bid advertiser from targeting your site as well, or even no one targeting your site.

Bear in mind, however, that PR is not related to any of this process.

I had read in a post a while ago and was concerned cause I re-activated my Adwords.