Test 3
Review
1. A family has three children. Using b to stand
for boy and g to stand for girl, and using ordered triples such
as bbg, find the following:
a. draw a tree diagram to
determine the sample space
b. the event E that the family has exactly two boys
c. the event F that the family has at least two boys
d. the event G that the family has three boys
e. p(E)
f. p(F)
g. p(G)
h. the probability that there are exactly two boys given that the
first child is a girl
2. Mendel found that snapdragons have
no color dominance; a snapdragon with one red gene and one white gene
will have pink flowers. If a pure red snapdragon is crossed with
a pink snapdragon, find the following probabilities.
a. a red offspring
b. a white offspring
c. a pink offspring
3. If a single card is drawn from a
deck of 52 cards, find each of the following probabilities:
a. a black card
b. a heart
c. a queen
d. a card below a 5 (count an ace as high)
e. a card above a 9 (count an ace as high)
f. a card below a 5 and above a 9 (count an ace as high)
g. a card is below a 5 or above a 9 (count an ace as high)
4. Alex is taking two courses, algebra
and U. S. history. Student records indicate that the probability
of passing algebra is 0.25; that of failing U. S. history is 0.45, and
that of passing at least one of the two courses 0.80. Find the
probability of each of the following.
a. Alex will pass history.
b. Alex will pass both courses.
c. Alex will fail both courses.
d. Alex will pass exactly one course.
5. On the basis of his previous
experience, the public librarian at Smallville knows that the number of
books checked out by a person visiting the library has the following
probabilities.
Number of Books
|
0
|
1
|
2
|
3
|
4
|
5
|
Probability
|
0.05
|
0.15
|
0.25
|
0.35
|
0.05
|
0.15
|
Find the expected number of books checked out by a person visiting this
library.
6. A group of 600 people were surveyed about violence on
television. Of those women surveyed, 256 said there was too much
violence, 45 said that was not too much violence, and 19 said they
don't know. Of those men surveyed 162 said there was too much
violence, 95 said that there was not too much violence, and 23 said
they don't know.
a. What is the probability
that a person surveyed was a woman and thought there was not too much
violence on television?
b. What is the probability that a person thought there was too
much violence on television given that the person was a woman?
c, What is the probability that a person who was a man thought
that there was not too much violence on television?