Reference no: EM132233073

Statistics Questions -

Q1) Approximately how much of the total area under the normal curve will be in the interval spanning two standard deviations on either side of the mean?

A. 99.7%

B. 95.5%

C. 50%

D. 68.3%

Q2. According to driver safety statistics in a particular area, one percent of drivers reported that they never wear their seatbelts. If two drivers are randomly selected, what's the probability that both of them will be wearing a seatbelt?

A. .048

B. .052

C. .001

D. .8116

Q3. Find the z-score that determines that the area to the right of z is 0.8264.

A. -1.36

B. 1.36

C. -0.94

D. 0.94

Q4. From an ordinary deck of 52 playing cards, one is selected at random. What's the probability that the selected card is either an ace, a queen, or a three?

A. 0.0769

B. 0.3

C. 0.2308

D. 0.25

Q5. Assume x is a normally distributed random variable with mean = 11 and variance = 2. Find P(6 ≤ x ≤ 10).

A. .3023

B. .1525

C. .3830

D. 0

	Brown-haired	Blond
Short-haired	0.06	0.23
Shaggy	0.51	0.20

Q6. A breeder records probabilities for two variables in a population of animals using the two-way table given here. Let A be the event "shaggy and brown-haired." Compute P(A^c).

A. 0.77

B. 0.49

C. 0.51

D. 0.36

Q7. Let event A = rolling a one 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. On a Venn diagram, event A would overlap event B.

B. On a Venn diagram, event B would contain event A.

C. Events A and B are exhaustive.

D. Events A and B are mutually exclusive.

Q8) You take a random sample of 100 observations from a population with a mean of 30 and a standard deviation of 16. What's the probability P(22.1 ≤ x ≤ 26.8)?

A. .0495

B. .0228

C. .025

D. .0554

Q9. 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 end sheet, identify the relevant z value.

A. 0.0675

B. -0.0675

C. 0.44

D. 0.255

	Brown-haired	Blond
Short-haired	0.06	0.23
Shaggy	0.51	0.20

Q10. 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's the probability that it's short-haired

A. 0.105

B. 0.222

C. 0.06

D. 0.0306

Q11. Assume x is a normally distributed random variable with mean = 50 and variance = 3. Find the value of the random variable x₀ when P(x ≤ x₀) = .8413

A. 16

B. 33

C. 53

D. 49

Q12. A random sample of 40 hotel reviews is drawn from a large population of hotel customers. It's known that 30% of the population left the hotel 1 star, 20% left 2 stars, 20% left 3 stars, and 30% left 4 stars. Give the hotel's average star rating.

A. 2

B. 3

C. 2.5

D. 3.5

Q13. Consider an experiment that results in a positive outcome with probability 0.38 and a negative outcome with probability 0.62. Create a new experiment consisting of repeating the original experiment 3 times. Assume each repetition is independent of the others. What's the probability of three successes?

A. 1.14

B. 0.055

C. 0.762

D. 0.238

Q14. A random sample of 40 hotel reviews is drawn from a large population of hotel customers. It's known that 30% of the population left the hotel 1 star, 20% left 2 stars, 20% left 3 stars, and 30% left 4 stars. Give the standard deviation of the hotel's star rating.

A. .1893

B. .1904

C. .1934

D. .1891

Q15. 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. 0.817

B. 0.815

C. 0.759

D. 0.191

Q16. If x is a binomial random variable, find p(x) when n = 4, x = 2, and q = .4

A. .027

B. .3456

C. .1611

D. .644

Q17. For each car entering the drive-thru of a fast food restaurant, x = the number of occupants. In this study, x is a

A. joint probability.

B. continuous quantitative variable.

C. dependent event.

D. discrete random variable.

Q18. Assume a random sample of n measurements is selected from a population with a mean of 20 and a standard deviation of 40. What's σ_x^-?

A. 20

B. 8

C. 16

D. 10

Q19. 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?

A. 18

B. 22

C. 10

D. 0

Q20. 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?

A. 15.9%

B. 47.8%

C. 68.3%

D. 94.8%