Intro to Stats
Addition Rule
Name __________________
1)
In a group of 100 people; 19 were drinking punch and 23 were eating fish. Find the
probability that a people picked from this group at random is either drinking punch or
eating fish?
2)
In a group of 92 students 40 have brown eyes and 35 have hazel eyes. Find the
probability that a student picked from this group at random either has hazel or brown
eyes?
3)
One hundred students were surveyed about their preference between dogs and cats.
Make a two-way table that displays data for the sample of students who responded to
the survey. Of those that preferred dogs, 36 were male and 20 were female. There were
10 males and 26 females that preferred cats. There were 8 students who had no
preference, 2 of those were male.
a) P(prefers dogs)=
b) In this sample, are the events "prefers dogs" and "prefers cats" mutually exclusive?
c) P(prefers dogs or cats)=
d) In this sample, are the events "prefers dogs" and "female" mutually exclusive?
e) P(prefers dogs or is female)=
Shade the following Venn Diagrams.
4) P(A’)
A
5) P(A U B)’
B
A
B
6) Several people were surveyed and the results
were put into a Venn Diagram. Answer the
following questions based on on the venn diagram.
A
5
4
35
B
9
10
17
a)
How many people were surveyed?
b)
How many people belong in set A’?
c)
How many people belong in set A?
d)
P(B)?
e)
P(B U C)?
f)
P(B ∩ C)?
g)
P(C’)?
h)
P(B’ ∩ C)
C
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