Statistics and Probability Entry Ticket

Which of the following is TRUE about a random variable?

• A. Possible values are not determined by chance.

• B. Typically represented by lowercase letter, usually x.

• C. A random variable may be discrete or continuous

• D. Represented by a negative value.

Random variables can either be discrete or continuous. Which of the following best describes a discrete random variable?

• A. can assume an infinite number of values in an interval between two specific values

• B. can assume values that can be represented by whole numbers

• C. the time it takes a teacher to construct his test in Statistics and Probability

• D. a variable that can only take a finite number of distinct values

Suppose you are taking a quiz with two multiple choice questions, and each question has 4 possible answers and only one of which is correct. Let x represent the number of correct answers in the quiz. What are the possible values of the random variable, x?

• A. 0, 1, 2

• B. 0, 1

• C. 0, 2

• D. 1, 2

Which of the following is TRUE about the properties of the probability distribution?

(i) each probability is less than zero

(ii) the sum of the probabilities is equal to 1

• A. (i) only

• B. (ii) only

• C. Both (i) and (ii)

• D. Neither (i) nor (ii)

If a coin is tossed, which of the following is the probability of getting a head?

• 0.25

• 0.50

• 0.75

• 1.00

The mean or the expected value of the probability distribution is given by what formula?

• 
• 
• 
• 

Calculate the variance of the probability distribution of the table.

• 0.50

• 1.0

• 1.5

• 2.0

Solve for the mean of the probability distribution below.

• A. 2.38

• B. 2.40

• C. 2.42

• D. 2.44

Solve for the variance of the probability distribution.

• A. 0.93

• B. 0.92

• C. 0.91

• D. 0.90

Which of the following is NOT true about the characteristics of the normal random variable?

• A. The normal curve is bell-shaped.

• B. The mean, median, and mode are at the highest point of the curve.

• C. The area under the curve is 100.

• D. The spread of the curve depends on the standard deviation