1. Consider an experiment that results in a positive outcome with probability 0.38 and a negative outcomewith probability 0.62. Create a new experiment consisting of repeating the original experiment 3 times.
Assume each repetition is independent of the others. What is the probability of three successes?
A. 0.055
B. 0.238
C. 0.762
D. 1.14
2. Which of the following is correct concerning the Poisson distribution?
A. The mean is usually smaller than the variance.
B. Each event being studied must be statistically dependent on the previous event.
C. The mean is usually larger than the variance.
D. The event being studied is restricted to a given span of time, space, or distance.
3. The Burger Bin fast-food restaurant sells a mean of 24 burgers an hour and its burger sales are normallydistributed. If hourly sales fall between 24 and 42 burgers 49.85% of the time, the standard deviation is_______ burgers.
A. 6
B. 3
C. 18
D. 9
4. A credit card company decides to study the frequency with which its cardholders charge for items froma certain chain of retail stores. The data values collected in the study appear to be normally distributed witha mean of 25 charged purchases and a standard deviation of 2 charged purchases. Out of the total numberof cardholders, about how many would you expect are charging 27 or more purchases in this study?
A. 47.8%
B. 94.8%
C. 68.3%
D. 15.9%
5. If the mean number of hours of television watched by teenagers per week is 12 with a standard deviationof 2 hours, what proportion of teenagers watch 16 to 18 hours of TV a week? (Assume a normaldistribution.)
A. 0.3%
B. 2.1%
C. 4.5%
D. 4.2%
6. A basketball team at a university is composed of ten players. The team is made up of players who playthe position of either guard, forward, or center. Four of the ten are guards, four are forwards, and two arecenters. The numbers that the players wear on their shirts are 1, 2, 3, and 4 for the guards; 5, 6, 7, and 8for the forwards; and 9 and 10 for the centers. The starting five are numbered 1, 3, 5, 7, and 9. Let aplayer be selected at random from the ten. The events are defined as follows:
Let A be the event that the player selected has a number from 1 to 8.
Let B be the event that the player selected is a guard.
Let C be the event that the player selected is a forward.
Let D be the event that the player selected is a starter.
Let E be the event that the player selected is a center.
Calculate P(C).
A. 0.40
B. 0.50
C. 0.20
D. 0.80
7. Tornadoes for January in Kansas average 3.2 per month. What is the probability that, next January,
Kansas will experience exactly two tornadoes?
A. 0.2226
B. 0.4076
C. 0.2087
D. 0.1304
8. From an ordinary deck of 52 playing cards, one is selected at random. What is the probability that theselected card is either an ace, a queen, or a three?
A. 0.3
B. 0.25
C. 0.2308
D. 0.0769
9. A continuous probability distribution represents a random variable
A. that's best described in a histogram.
B. having an infinite number of outcomes that may assume any number of values within an interval.
C. that has a definite probability for the occurrence of a given integer.
D. having outcomes that occur in counting numbers.
10. The Burger Bin fast-food restaurant sells a mean of 24 burgers an hour and its burger sales arenormally distributed. The standard deviation is 3.061. What is the probability that the Burger Bin will sell12 to 18 burgers in an hour?
A. 0.239
B. 0.136
C. 0.475
D. 0.342
11. A breeder records probabilities for two variables in a population of animals using the two-way tablegiven here. Let A be the event ""shaggy and brown-haired."" Compute P(Ac).
Brown-haired Blond
Short-haired 0.06 0.23
Shaggy 0.51 0.20
A. 0.51
B. 0.77
C. 0.49
D. 0.36
12. A breeder records probabilities for two variables in a population of animals using the two-way tablegiven here. Given that an animal is brown-haired, what is the probability that it's short-haired?
Brown-haired Blond
Short-haired 0.06 0.23
Shaggy 0.51 0.20
A. 0.06
B. 0.222
C. 0.0306
D. 0.105
13. In the binomial probability distribution, p stands for the
A. number of trials.
B. probability of success in any given trial.
C. probability of failure in any given trial.
D. number of successes.
14. The possible values of x in a certain continuous probability distribution consist of the infinite number ofvalues between 1 and 20. Solve for P(x = 4).
A. 0.03
B. 0.05
C. 0.02
D. 0.00
15. An apartment complex has two activating devices in each fire detector. One is smoke-activated and hasa probability of .98 of sounding an alarm when it should. The second is a heat-sensitive activator and has aprobability of .95 of operating when it should. Each activator operates independently of the other. Presumea fire starts near a detector. What is the probability that both activating devices will work properly?
A. 0.965
B. 0.931
C. 0.9895
D. 0.049
16. What is the value of ?
A. 1.6
B. 56
C. 336
D. 6720
17. The probability of an offender having a speeding ticket is 35%, having a parking ticket is 44%, havingboth is 12%. What is the probability of an offender having either a speeding ticket or a parking ticket orboth?
A. 91%
B. 67%
C. 79%
D. 55%
18. For each car entering the drive-through of a fast-food restaurant, x = the number of occupants. In thisstudy, x is a
A. dependent event.
B. continuous quantitative variable.
C. joint probability.
D. discrete random variable.
19. Each football game begins with a coin toss in the presence of the captains from the two opposingteams. (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 thatthe team captain wins during the season. Using the appropriate table in your textbook, solve for P(4 = x =
8).
A. 0.377
B. 0.171
C. 0.246
D. 0.817
End of exam
Protestant Catholic Jewish Other
Democrat 0.35 0.10 0.03 0.02
Republican 0.27 0.09 0.02 0.01
Independent 0.05 0.03 0.02 0.01
20. The table above gives the probabilities of combinations of religion and political parties in a city in theUnited States. What is the probability that a randomly selected person will be a Protestant and at the sametime be a Democrat or a Republican?
A. 0.89
B. 0.35
C. 0.62
D. 0.67