To find out how many books of each subject the librarian likely has in the box, we need to determine the probability of selecting a book from each subject.
The total frequency of all subjects is 40 + 16 + 20 + 36 = 112.
The probability of selecting a book from each subject is:
- Science: 40/112 = 0.3571
- Math: 16/112 = 0.1429
- History: 20/112 = 0.1786
- Reading: 36/112 = 0.3214
Now we multiply these probabilities by the total number of books (28) to find how many books of each subject the librarian likely has:
- Science: 0.3571 * 28 ≈ 10 books
- Math: 0.1429 * 28 ≈ 4 books
- History: 0.1786 * 28 ≈ 5 books
- Reading: 0.3214 * 28 ≈ 9 books
Therefore, according to the probability model, the librarian likely has approximately 10 books on Science, 4 books on Math, 5 books on History, and 9 books on Reading in the box.
A librarian has a box of books on four subjects: science, math, history, and reading. She conducts a probability experiment in which for each event, she randomly picks one book from the box, records the subject, and then replaces it. The results are shown in the table.
Subject Frequency
Science 40
Math 16
History 20
Reading 36
Based on the probability model, how many books of each subject does she likely have if she has 28 books in the box?
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