Google Play rating calculations are different for public vs private ratings, as per the image below.
Public Ratings shows the Ratings which match what you see on the public page for that app in the app store – the same rating users who are browsing the app store will see. For Google Play apps the Public Google Play rating calculations show a weighted average value The details of the weighted average calculation are not made publicly available by Google. Public ratings are only available in Appbot after Google’s moderation process.
Private Ratings means the Ratings that match what you see inside your developer console. Here, the Google Play rating calculations are done without applying any weightings to the average. The private data sometimes also shows a higher count of Ratings, as new Ratings appear in the console before they are seen publicly. Private ratings are available in Appbot before Google’s moderation process.
For authenticated apps “Private” will be selected by default. More information on authenticating your Google Play apps can be found here.