Statistics and Probability:
Random Variables and Probability Distributions
Random Variable
- It is a result of chance event that you can measure or count.
- It is a numerical quantity that is assigned to the outcome of an experiment. It is
a variable that assumes numerical values associated with the events of an experiment.
- It is a quantitative variable which depends on change.
What I Know
A.
If two coins are tossed once, which is NOT a possible value of the random
variable for the number of heads?
a. 0 b. 1 c. 2 d. 3
Answer: 3
Solution:
Let H represent the number of heads that will come out. Determine the values of
the random variable H.
Steps Solution
1. List the sample space S= {TT, TH, HT, HH}
2. Count the number of heads in
each outcome and assign this
number to this outcome
Outcome Number of
Heads
(Value of H)
HH 2
HT 1
TH 1
TT 0
3. Conclusion The values of the random variable H
(number of heads) in this experiment
are 0, 1, and 2.
Which of the following is a discrete random variable?
a. Length of wire ropes
b. Number of soldiers in the troop
c. Amount of paint used in repainting the building
