Aprofessor using an open source introductory statistics book predicts that 10% of the students will purchase a hard copy of the book, 55% will print it out from the web, and 35% will read it online. at the end of the semester he asks his students to complete a survey where they indicate what format of the book they used. of the 200 students, 25 said they bought a hard copy of the book, 85 said they printed it out from the web, and 90 said they read it online.