4. Probability
If P(A) =1, then the event is
certain to occur.
If P(A) =0, then the
event cannot occur.
5. How do we express probabilities?
1.Usually, we express probabilities as fractions.
2.The numerator shows the POSSIBLE number of ways
an event can occur.
3.The denominator is the TOTAL number of possible
events that could occure.
6. P(E)=Probability of an event
When, P(E) =
0, An event that is uncertain to happen
P(E) =1,An event that is certain to happen
Formula:
P(E)= POSSIBLE number of ways an event can
occur/TOTAL number of possible events
7. How do we describe probability?
.You can describe the probability of an event with
the following terms:
1.certain (the event is definitely going to
happen) likely (the event will probably happen,
but not definitely)
2.unlikely (the event will probably not
happen, but it might)
3.impossible (the event is definitely not going to
happen).
8. Example of Dice
Probability(1/6)
for each number 1-6
1=
Each number on a dice :(1,2,3,4,5,6)
6=
Total number of sides
Probability of
Even Numbers:
P(3/6)or>(1/3)
Probability of ODD
numbers:
P(1/3)or>(1/3)
9. Example of Dice
When a coin is tossed, there are two possible
outcomes: Heads and Tails P(Heads) =½
