Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
Facebook was easy to appy to the Tablet, but since I decided to gift the Tablet to my Granddaughter for her Birthday, a Wonderful Product, by the way, but me being 80 years old decided it was not like my Lap Top, and I did not want to Learn how to work the Tablet, so gifted it to my Granddaughter. She LOVES it. Therefore before gifting it, I remove my Facebook App and Un-Registered the Tablet from me, so she could Register to her. She is an avid Amazon Shopper also so should not be an issue for her to Register it herself.