Math 11 Probability and Statistics Quiz

Which of the following best describes a random variable?

• A variable that can take on multiple values
• A variable that is always constant
• A variable that is dependent on another variable
• A variable that can only take on one value

What is the primary difference between discrete and continuous random variables?

• Discrete variables are countable, while continuous variables are not
• Continuous variables are countable, while discrete variables are not
• Both are countable
• Neither are countable

Which of the following is NOT an example of a continuous random variable?

• Height of a person
• Weight of a bag of rice
• Number of students in a classroom
• Temperature of a room

What does the mean of a random variable represent?

• The most frequent outcome
• The average of all possible outcomes weighted by their probabilities
• The highest possible outcome
• The lowest possible outcome

If the probability of an event is 0.25, what is the probability of the event not occurring?

• 0.25
• 0.50
• 0.75
• 0.80

In a probability mass function, what type of graph is typically used?

• Line graph
• Bar graph
• Pie chart
• Histogram

What is the variance of a random variable?

• The square root of the standard deviation
• The average of the squared deviations from the mean
• The sum of all possible outcomes
• The difference between the highest and lowest outcomes

What does a z-score indicate?

• The position of a value relative to the mean
• The probability of a value occurring
• The total number of outcomes
• The average of all outcomes

If a z-score is negative, what does it imply about the corresponding value?

• It is above the mean
• It is below the mean
• It is equal to the mean
• It is the highest value

How do you find the area under the standard normal curve between two z-scores?

• Add the areas of both z-scores
• Subtract the area of the lower z-score from the area of the upper z-score
• Multiply the areas of both z-scores
• Use the mean and standard deviation