Download Ch6 Probability Review Name: Government data give the following

Ch6 Probability Review
Name:______________________
Government data give the following counts of violent deaths in a recent year among
people 20 to 24 years of age by sex and cause of death:
Female
Accidents 1818
Homicide 457
Suicide
345
Male
6457
2870
2152
Questions 1 to 4 are based on this table. Show work and probability notation.
1. Choose a violent death in this age group at random. The probability that the
victim was male is?
2. The conditional probability that the victim was male, given that the death
was accidental, is?
3. The conditional probability that the death was accidental, given that the
victim was male, is?
4. Let A be the event that a victim of violent death was a woman and B the event
that the death was a suicide. The proportion of suicide among violent deaths
of women is expressed in probability notation as?
5. Choose an American adult at random. The probability that you choose a
woman is 0.52. The probability that the person you choose has never
married is 0.24. The probability that you choose a woman who has never
married is 0.11. The probability that the person you choose is either a
woman or never married (or both) is?
6. Event A occurs with probability 0.2. Event B occurs with probability 0.8. If A
and B are disjoint (mutually exclusive), then
A. P(A and B) = 0.16
B. P(A or B) = 1.0
C. P(A and B) = 1.0
D. P(A or B) = 0.16
E. Both (A) and (B) are true.
7. A die is loaded so that the number 6 comes up three times as often as any
other number. What is the probability of rolling a 1 or a 6?
Questions 8 and 9 refer to the following: In a particular game, a fair die is tossed. If
the number of spots showing is either four or five, you win $1. If the number of
spots showing is six, you win $4. And if the number of spots showing is one, two, or
three, you win nothing. You are going to play the game twice.
8. The probability that you win $4 both times is
9. The probability that you win at least $1 both times is
Questions 10 and 11 relate to the following: An event A will occur with probability
0.5. An event B will occur with probability 0.6. The probability that both A and B wil
occur is 0.1.
10. The conditional probability of A, given B
11. We may conclude that
A. events A and B are independent
B. events A and B are disjoint
C. either A or B always occurs
D. events A and B are complementary.
E. None of the above is correct.
12. A coin tossed five times.
(a) Find the probability of getting at least one tail.
(b) Find the probability of getting exactly 4 tails.
13. Approximately 30% of the calls to an airline reservation phone line result in
a reservation being made.
(a) Suppose that an operator handles 10 calls. What is the probability that none
of the 10 results in a reservation?
(b) What assumption did you make in order to calculate the probability in (a)?
(c) What is the probability that at least one call results in a reservation being
made?
14. Experience has shown that a certain lie detector will show a positive reading
(indicates a lie) 10% of the time when a person is telling the truth and 95%
of the time when a person is lying. Suppose that a random sample of 5
suspects is subjected to a lie detector test regarding a recent one-person
crime. Then the probability of observing no positive reading if all suspects
plead innocent and are telling the truth is
15. If you buy one ticket in the Provincial Lottery, then the probability that you will
win a prize is 0.11. If you buy one ticket each month for five months, what is the
probability that you will win at least one prize?