Probability
is the chance that an event will happen.
An
event is something that
happens in an experiment that brings about an outcome.
Example
1: Event
You go
shopping at the grocery store.
An
event is something that happens.
Example 2:
Certain
You will sleep.
Think: You have to sleep to live.
An event is
certain if it will always happen.
The probability
of an event that is certain is 1.
Example 3:
Impossible
You will see a cow
jumping over the moon.
Think: Cows do not fly or jump.
An event is
impossible if it will never happen.
The probability
of an event that is impossible is
0.
Example
4: Sometimes
You will see
rain on Mondays.
Think: Sometimes it will rain on
Mondays and sometimes it will not rain
on Mondays.
An event
happens sometimes if it doesn't happen
all the time.
The probability
of an event that sometimes happens is
greater than 0 and less than 1.
Example for
Certainty, Impossibility, and Sometimes
What is the probability of spinning
a 1or 2 or 3 or or 4? What is the probability of spinning a 5?
What is the probability of spinning just a 2?
It is
certain that the spinner will land on 1 or 2 or 3 or 4.
It is
impossible that the spinner will land on 5.
Sometimes
when you spin the spinner in may land on 2.
Remember:
An event is
certain if it will always happen.
An event is
impossible if it will never happen.
An event happens sometimes if it
doesn't happen all the time.
Probability
