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Random variable is random variable

1. RANDOM
VARIABLE

2. 3
OBJECTIVES:
2
4
Illustrates a random variable,
finds the possible values of a
random variable.
distinguishes between a discrete
and a continuous random variable,
1 Define random variable

3. Review
1)
2)

Aside from decimal , probability
may be expressed as these two.
3) The possible outcomes of an
experiment.
4) Set of possible outcomes of an
experiment.
5) Tells how often a certain event will
happen.
FRACTION
PERCENTAGE
EVENT
SAMPLE SPACE
PROBABILITY

4. RANDOM VARIABLE
Is a variable that assumes numerical values associated with
the random outcomes of an experiment, where one (and
only one) numerical value is assigned to each sample point.
Is the result of a chance event, that you can measure or
count.
We use uppercase letter to denote random variables.
Examples:
�=
� �� �� �����
� �� �� ����

�=�������� ���??????��� � ��� �
�={�,�,�,�}
�=??????����� �� ??????��� � ��?????? ���� ���� �=�.�≤�≤�.�
�= {�,�}

5. Guess me right!
Discrete Continuous
Mistakes per
page
The thickness of a
book
The number of
bottled water in a
box
People queuing
Your height
The depth of water
in the ocean
Number of words
in an essay
Discrete- can assume a countable number of values.
Continuous- have an infinite continuum of possible values.

6. ODD ONE OUT
Number of
push ups you
can do in five
minutes
Let’s Exercise
Number of
days in a
week you
exercise
Amount of
calories
burned after
an exercise
Number of
steps for a
15-minute
walk

7. ODD ONE OUT
How fast can
a sneeze
spread
germs?
Science Matters
How long does
the virus that
causes COVID-
19 last on
surfaces?
Stay at least 1
meter distance
to avoid contact
with droplets
Number of
ways a virus
may be
transmitted

8. Time before
you received
an email from
your colleague
ICT Version
Distance
reached by Wi-
Fi connection
Length of cable
from the server
to working
station
Number of
e-mails sent
in a day
ODD ONE OUT

9. ODD ONE OUT
The volume of
gasoline in a
Honda Beat
Motorcycle.
Road Trip
The number of
motorists that
gas up today.
The distance
travelled with a
full tank
motorcycle.
The length of
time between
motorists in a
gasoline station
ODD ONE OUT

10. ODD ONE OUT

I am 150 cm
tall.
Me, Myself, and I

I weigh 56
kilograms.

I have two
wonderful
sons.

My foot
measures 9
inches.
ODD ONE OUT

11. POSSIBLE VALUES OF RANDOM VARIABLE
1. Tossing a coin. Name the random
variable T.
??????=
0 �� ����
1 �� ����
??????={0,1}
2. Rolling a die.
??????=��� ������ ����� �� ��� ��� ����
??????={1,2,3,4,5,6}

12. POSSIBLE VALUES OF RANDOM VARIABLE
3. Couple plans to have 3 children.
??????=��� ������ �� ����� ��� ������ ��?????? ����
BBB
BBG
BGB
BGG
GBB
GBG
GGB
GGG
0
1
1
2
1
2
2
3
??????={�,�,�,�}
B
G
B
G
B
G
G
G
G
B
B
B
BBB
BBG
BGB
BGG
GBB
GBG
GGB
GGG
B
G