I am currently inserting a star rating of various vendors using the following formula New
New Rating Value = ((Overall Rating * Total Rating) + New Calculated ) / Total Rating
Overall Rating = Current Rating value Total Rating = No of reviews (ratings) currently present New Calculated = The new star rating value the user specified
The above formula works for adding a new rating. My question is how would I remove a specific rating and return to the old value if I only have the
New Calculated and the total Rating value (I wont have access to the earlier Overall Rating ?