ap statistics section 6.3 a probability addition rules
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AP Statistics Section 6.3 A Probability Addition Rules. Recall these rules of probability :. Consider the table at the right about Nobel Prize winners. If one winner is selected at random, find …. P(from the U.S.) = P(in medicine) = P (from the U.S. or in medicine) =. - PowerPoint PPT PresentationTRANSCRIPT
AP Statistics Section 6.3 A
Probability Addition Rules
Recall these rules of probability:
0 1 1
P(B)P(A)
P(A)-1
P(B)P(A)
Consider the table at the right about Nobel Prize winners. If one winner is selected at random, find….
P(from the U.S.) =
P(in medicine) =
P (from the U.S. or in medicine) =
366
215
122
45
366
135
366
135
366
215
183
130
366
260
366
90
If events A and B are not disjoint, then they have some outcomes in
common.
NEW and IMPROVED ADDITION RULE:
Note: If A and B are disjoint, then
and the Addition Rule above is obtained.
)()()( BAPBPAP
0
We can use Venn diagrams to illustrate non-disjoint events.
Example 1: The probability that Deborah is promoted, P(D) , is 0.7. The probability that Matthew is promoted,
P(M) , is 0.5. The probability that both Deborah and Matthew are promoted, P(D and M), is 0.3.
3.Deb
.4Matt
.2
Find P(Deborah is promoted but Matthew is not)
4.
Find P(that at least one of them is promoted)
Matt)or P(Deb
9.3.5.7.
Find P(neither one is promoted)
1.9.1
2.
Example 2: Stephanie is graduating from college. Here are the probabilities for her obtaining three jobs.
Example 2: Stephanie is graduating from college. Here are the probabilities for her obtaining three jobs.
A B
C
0
2.
05. 05.
35. 25.
1.
(a) P(Stephanie is offered at least one of three jobs)
(b) P(Stephanie is offered jobs A and B but not C)
11.05.05.025.2.35.
2.