[填空题]
A group of chemistry students at Indiana Uniq/vykqk.gnp,/ :p391ke dtg q versity cys.gm nx4 q3ne 6/pc*Bloomington were surveyed. They were asked which of the following textbook formats: e-textbook ( E ), paperback (Px g6qney/ 3ps*4. cmcn) or hardcover (H) , they used in their courses.
The following results were obtained:
108 students used paperback
64 students used hardcover
45 students used paperback and hardcover
68 students used e-textbook and paperback
49 students used e-textbook and hardcover
35 students used all three textbook formats
18 students used e-textbook only
15 students used none of the three textbook formats
1. Use the above information to complete a Venn diagram.
2. Calculate the number of students who were surveyed.
3. 1. On your Venn diagram, shade the set $(E \cup P) \cap H^{\prime}$ .
2. Find $n\left((E \cup P) \cap H^{\prime}\right)$ .
4. A chemistry student who was surveyed is chosen at random. Find the probability that
1. the student used an e-textbook; ≈
2. the student used a hardcover, given that they had not used an e-textbook;
3 . the student used at least two of the textbook formats.
The Chemistry Department at IU Bloomington has 2560 students.
5. Find the expected number of students in the Chemistry Department that used e-textbooks. ≈
