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.
Alhamdulillah it is very good read about Islam. The only problem is about the kindle edition, my becomes unresposive quite frequently while is read this book. It doesn't happen with any other book. If you can fix/update, please let me know so that I can re download.