Probability Review

What is a random variable?

• A variable that changes randomly with time.

• A variable whose outcome is determined by a random experiment.

• A variable with a fixed value.

• A variable that follows a uniform distribution

If a probability distribution is uniform, this means:

• All outcomes have equal probabilities.

• The distribution is skewed.

• Some outcomes have zero probability.

• Probabilities increase linearly.

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

• It has two modes.

• The total area under the curve is less than 1.

• It is defined only for discrete data.

• It is symmetric around the mean.

How would you solve if the problem is: From the 20 DVD's you purchased this past year, you plan to take five with you on vacation.  How many different sets of five DVD's can you take?

• Fundamental Counting Principle

• Permutation

• Combination

• Factorial

Which of the following is an example of combination?

• Choose 4 students in a class committee.

• Students line up in a queue to assembly.

• Form a passcode with 4 digits.

• Choose the chairperson, secretary and treasurer in a club.

How would you solve the problem: The batting order for seven players on a 12-person team?

• Fundamental Counting Principle

• Permutation

• Combination

• Factorial

In how many ways in selecting 4 desserts from 10 possible choices displayed on the dessert cart at a restaurant.

• 630

• 360

• 120

• 210

What is the number of distinct permutations of the word "PERFECT"?

• 2 520

• 420

• 1 042

• 250

Seven beads, no two of which are the same, will be put together to form a bracelet without a lock. How many ways can the beads be arranged?

• 360

• 720

• 2 520

• 5 040

Which statement about discrete and continuous variables is true?

• Discrete variables are uncountable.

• Discrete variables represent measurements.

• Continuous variables can only take a finite number of values.

• Continuous variables are used when measurements are involved.