12.1. What is a Discrete Random Variable?

Try these first

1. 1.

   What is a discrete random variable?

   Hint

   Think of outcomes you can list down.

2. 2.

   Provide an example of a discrete random variable.

   Hint

   Consider simple experiments.

3. 3.

   What type of values can a discrete random variable take?

   • Countable
   • Uncountable
   • Both

   Hint

   Think about how we can list these outcomes.

4. 4.

   True or False: PMFs apply to both discrete and continuous random variables.

   • True
   • False

   Hint

   Recall the definitions of PMF.

5. 5.

   If a die is rolled twice, what is the PMF for the sum of the outcomes?

   Hint

   What sums can result from rolling two dice?

6. 6.

   In a digital communication system, if the probability of packet loss is 0.1, what is the PMF for the number of packets lost out of 10 packets?

   Hint

   How does the binomial formula apply here?