3. A bookstore sells two types of books (fiction and nonfiction) in several formats
(hardcover, paperback, digital, and audio). Consider an experiment that consists of
observing the type and format of a single book purchase, two possible outcomes are a
hardcover fiction book and an audio fiction book. The number of all outcomes the
sample space would include is:
(a) 4
(b) 16
(c) 32
(d) 8
(e) 12
4. Consider problem 3. For customers who purchase a single book, the estimated
probabilities for different possible outcomes are given in the table below.
Hardcover Paperback Digital Audio
Fiction
Nonfiction
0.15 0.45 0.10 0.10
0.08 0.04 0.02 0.06
What is the probability that a randomly selected single‐book purchase will be for a book in
print format (hardcover or paperback)?
(a) 0.60
(b) 0.23
(c) 0.49
(d) 0.32
(e) 0.72
8.15
3. To determine the number of outcomes in the sample space, we need to multiply the number of options for each category.
For the type of book, there are 2 options (fiction and nonfiction).
For the format of the book, there are 4 options (hardcover, paperback, digital, and audio).
Therefore, the total number of outcomes in the sample space is 2 (types) * 4 (formats) = 8 outcomes.
So the correct answer is (d) 8.
4. To find the probability that a randomly selected single-book purchase will be in print format (hardcover or paperback), we need to sum the probabilities of those two formats.
From the given table, the probability of a single-book purchase being a hardcover fiction book is 0.15, and the probability of it being a paperback fiction book is 0.45.
Therefore, the probability of a randomly selected single-book purchase being in print format (hardcover or paperback) is 0.15 + 0.45 = 0.60.
So the correct answer is (a) 0.60.