Search for the latest edition (e.g., 7th or 8th edition). Older editions (2nd or 3rd) from 1990 are out of copyright in very few jurisdictions, but modern editions are not.
The is one of the most sought-after digital textbooks in South Asian academia—for good reason. It transforms a frightening subject (Statistics) into a series of logical, repeatable puzzles. Basic Statistics By Nagar And Das Pdf