Review Exam on Statistics & Probability

What is a qualitative variable?

• A variable that can be measured numerically

• A variable that can take on a range of values

• A variable that represents categories or labels

• A variable that is continuous in nature

Which of the following is an example of a quantitative variable?

• Gender

• Temperature

• Nationality

• Religion

A discrete random variable can take on which of the following?

• Any value within a range

• A countable number of values

• Any real number

• Values that are categorically distinct

Which of these is an example of a continuous random variable?

• Number of students in a class

• Time taken to complete a task

• Number of heads in a coin toss

• Color of a car

What does a probability distribution describe?

• The correlation between two variables

• All possible values of a random variable and their associated probabilities

• The mean and standard deviation of a dataset

• The range of a set of data

A normal distribution is symmetrical about the:

• Mean

• Median

• Mode

• None of the above

Which of the following is a characteristic of a normal curve?

• It is skewed to the right

• It is bell-shaped

• It has more peaks than a bimodal distribution

• It only has one mode

In a normal distribution, the area under the curve represents:

• The number of observations

• The mean of the distribution

• The total probability of all outcomes

• The standard deviation

What is the difference between a population and a sample in statistics?

• A population is a subset of a sample

• A sample is the entire group being studied

• A population is the entire group, while a sample is a part of it

• There is no difference; they are the same

Which of the following describes a probability distribution?

• A set of probabilities for a qualitative variable

• A set of probabilities for a random variable

• A graph of data points and their frequencies

• A frequency distribution table