Working with Discrete Random Variables

What is a discrete random variable?

• A variable that can take any value within a given range.

• A variable that can take on a countable number of distinct values.

• A variable that is always continuous.

• A variable that is always deterministic.

Which of the following is true about combining normal random variables?

• The sum of two normal random variables is not normal.

• The sum of two normal random variables is always normal.

• The sum of two normal random variables is normal only if they are independent.

• The sum of two normal random variables is normal only if they have the same mean.