⛔STOP ⛔ Before you look at the answers make sure you gave this practice quiz a try so you can assess your understanding of the concepts covered in Unit 4. Click here for the practice questions:AP Statistics Unit 4 Multiple Choice Questions.
Facts about the test: The AP Statistics exam has 40 multiple choice questions and you will be given 1 hour 30 minutes to complete the section. That means it should take you around 11 minutes to complete 5 questions.
The following questions were not written by College Board and although they cover information outlined in the AP Statistics Course and Exam Description the formatting on the exam may be different.
1. Which of the following is the set of all possible outcomes of a given event?
A. Frequency Chart
B. Simulation Chart
C. Sample Space
D. Tree Diagram
Answer: A sample space is any way in which all possible outcomes of a given event are listed out.
2. Which of the following two events represents two events that are mutually exclusive?
A. December in FL and hurricane
B. January in CA and snow
C. November in NY and rain
D. July in AL and snow
Answer: July in AL and snow is an example of mutually exclusive events because they cannot occur at the same time. All of the other examples could occur and likely do at the same time.
3. If there are 6 items in a hat: 4 marbles (2 red and 2 blue) and 2 coins (1 red and 1 blue). What is the probability of drawing a marble or blue?
A. 5/6
B. 4/6
C. 1/6
D. 3/6
Answer: Since this is an or probability, otherwise known as a union of events, we take the 4 marbles and the 1 blue coin and add those up as our successes, which gives us 5/6. The red coin is the only option that doesn't fit our description.
5. Which of the following is not one of the classifications for a binomial distribution?
A. Independence
B. Clear success and failure
C. Normal Distribution
D. All trials equally likely of success
Answer: The binomial distribution is its own type of distribution, therefore, it does not follow a normal distribution always (it is usually skewed right instead of symmetric)
6. If a given random variable X has a mean of 3.2, what would the mean of random variable Y be if Y=X+5?
A. 3.5
B. 5.2
C. 3.2
D. 8.2
Answer: When transforming a random variable by addition, the mean changes based on that change. Scalar addition changes the mean, but not the standard deviation.
10. You are playing a game where you roll the dice, you win $5 if you get a 1 or a 6, $2 if you roll a 3 or -$2 if you roll a 2 or a 4. What is the expected value?
A. $10
B. $2
C. $1.33
D. $0
Answer: The expected value can be found by taking the sum of all possible outcomes multiplied by their individual probabilities: (2/6*5)+(1/6*2)+(2/6*-2).
12. If there are 6 red marbles and 12 blue marbles in a jar, what is the probability of drawing 3 red marbles (without replacement) from the jar in a row?
A. 0.043
B. 0.5
C. 0.33
D. 0.43
Answer: Since we are drawing three marbles without replacement, we would find the probability at each trial of selecting a red marble: 6/18 for the first trial, 5/17 for the second, 4/16 for the third and then multiply our three probabilities since these events are independent of each other.
13. Let X be the outcome of a regular dice. Find P(2<X<5).
A. 1
B. 0.5
C. 0.66
D. 0.33
Answer: Since the only options that are less than 5 and greater than 2 are 3 and 4, these are the two outcomes out of the 6 possible outcomes that satisfy our bounds. Therefore, 2/6=0.33
15. What data set would be an example of a continuous random variable?
A. Day of the week on which you were born
B. Shoe Size
C. Height
D. Grade in school
Answer: Since shoe size, day of the week for birthday and grade in school are all either whole numbers or categorical variables, they are discrete. Height is much more flexible (you could be 62.768 inches tall), so it is a continuous random variable.