1. The Burger Bin fast-food restaurant sells a mean of 24 burgers an hour and its burger sales are
normally distributed. What is the probability that the Burger Bin will sell 12 to 18 burgers in an hour?
The standard deviation should be given. Regardless of the standard deviation, the only possible
correct answer below is 0.136.
A. 0.239 B. 0.342 C. 0.136 D. 0.475
2. The probability of an offender having a speeding ticket is 35%, having a parking ticket is 44%,
having both is 12%. What is the probability of an offender having either a speeding ticket or a parking
ticket or both?
35% + 44% – 12% = 67%
A. 67% B. 91% C. 79% D. 55%
3. Tornadoes for January in Kansas average 3.2 per month. What is the probability that, next January,
Kansas will experience exactly two tornadoes?
e 3.2 3.2 2
 0.2087
2!
A. 0.4076 B. 0.2226 C. 0.2087 D. 0.1304
4. Which of the following is a discrete random variable?
A. The number of three-point shots completed in a college basketball game
B. The time required to drive from Dallas to Denver
C. The weight of football players in the NFL
D. The average daily consumption of water in a household
5. If the probability that an event will happen is 0.3, what is the probability of the event's
complement?
A. 1.0 B. 0.3 C. 0.1 D. 0.7
6. A basketball team at a university is composed of ten players. The team is made up of players who
play the position of either guard, forward, or center. Four of the ten are guards, four are forwards, and
two are centers. The numbers that the players wear on their shirts are 1, 2, 3, and 4 for the guards;
5, 6, 7, and 8
for the forwards; and 9 and 10 for the centers. The starting five are numbered 1, 3, 5, 7, and 9. Let a
player be selected at random from the ten. The events are defined as follows:
A = event player selected has a number from 1 to 8
B = event player selected is a guard
C = event player selected is a forward
D = event player selected is a starter
E = event player selected is a center
Calculate P(C).
A. 0.80 B. 0.40 C. 0.20 D. 0.50
7. Each football game begins with a coin toss in the presence of the captains from the two opposing
teams. (The winner of the toss has the choice of goals or of kicking or receiving the first kickoff.) A
particular football team is scheduled to play 10 games this season. Let x = the number of coin tosses
that the team captain wins during the season. Using the appropriate table in your textbook, solve for
P(4 ≤ x ≤ 8).
A. 0.246 B. 0.817 C. 0.377 D. 0.171
Brown-haired Blond
Short-haired 0.06 0.23 Shaggy 0.51 0.30
8. A breeder records probabilities for two variables in a population of animals using the two-way table
given here. Given that an animal is brown-haired, what is the probability that it's short-haired?
The table is incorrect since the probabilities do not sum to 1.
A. 0.222 B. 0.0306 C. 0.06 D. 0.107
9. The area under the normal curve extending to the right from the midpoint to z is 0.17. Using the
standard normal table on the textbook's back endsheet, identify the relevant z value.
1. A. –0.0675 B. 0.0675 C. 0.44 D. 0.4554
10. If the mean number of hours of television watched by teenagers per week is 12 with a standard
deviation of 2 hours, what proportion of teenagers watch 16 to 18 hours of TV a week? (Assume a
normal distribution.)
P((16-12)/2 < Z < (18-12)/2) = P(2 < Z < 3)
A. 4.5% B. 4.2% C. 2.1% D. 0.3%
11. Assume that an event A contains 10 observations and event B contains 15 observations. If the
intersection of events A and B contains exactly 3 observations, how many observations are in the
union of these two events?
10 + 15 – 3 = 22
A. 0 B. 22 C. 10 D. 28
12. In the binomial probability distribution, p stands for the
A. probability of success in any given trial.B. probability of failure in any given trial.
C. number of trials. D. number of successes.
13. Find the z-score that determines that the area to the right of z is 0.8264.
A. 1.36 B. –0.94 C. –1.36 D. 0.94
14. Let event A = rolling a 1 on a die, and let event B = rolling an even number on a die. Which of the
following is correct concerning these two events?
A. Events A and B are exhaustive.
B. On a Venn diagram, event B would contain event A.
C. On a Venn diagram, event A would overlap event B.
D. Events A and B are mutually exclusive.
15. From an ordinary deck of 52 playing cards, one is selected at random. Let the events be defined
as follows:
A = event card selected is an ace B = event card selected is a queen
C = event card selected is a three
What is the probability that the selected card is either an ace, a queen, or a three?
12/52
A. 0.25 B. 0.2308 C. 0.0769 D. 0.3
16. A continuous probability distribution represents a random variable
A. that has a definite probability for the occurrence of a given integer.
B. that's best described in a histogram.
C. having an infinite number of outcomes that may assume any number of values within an interval.
D. having outcomes that occur in counting numbers.
17. A credit card company decides to study the frequency with which its cardholders charge for items
from a certain chain of retail stores. The data values collected in the study appear to be normally
distributed with a mean of 25 charged purchases and a standard deviation of 2 charged purchases.
Out of the total number of cardholders, about how many would you expect are charging 27 or more
purchases in this study?
P(Z > (27 – 25)/2) = P(Z > 1)
A. 47.8% B. 94.8% C. 68.3% D. 15.9%
18. The Burger Bin fast-food restaurant sells a mean of 24 burgers an hour and its burger sales are
normally distributed. If hourly sales fall between 24 and 42 burgers 49.85% of the time, the standard
deviation is _______ burgers.
P((24 – 24)/σ < Z < (42 – 24)/σ) = P(0 < Z < 18/σ) = 0.4985
18/σ = 2.9677
σ = 18/2.9677 = 6
A. 6 B. 9 C. 3 D. 18
19. The possible values of x in a certain continuous probability distribution consist of the infinite
number of values between 1 and 20. Solve for P(x = 4).
A. 0.00 B. 0.02 C. 0.05 D. 0.03
20. Approximately how much of the total area under the normal curve will be in the interval spanning
2 standard deviations on either side of the mean?
A. 99.7% B. 68.3% C. 50% D. 95.5%