Name
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CC Algebra 2H
Problem Set 7-5 and Review
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Round answers to the nearest hundredth.
1. Pamela has collected data on the number of sophomores who
playa sport or a musical instrument.
a. Given that a student plays an instrument, what is the
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probability that the student also plays a sport?
55
-
~5
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b. Given that a student plays a sport, what is the
probability that the student does not play an instrument?
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5~
,
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c. Find the probability that a student plays a sport
or plays an instrument.
P(Sp'rf)
+ P(lnstru.YOO"'t) -
q~
2.b3
85
+
47
p( #1)
-
i03 -
203
bo
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~ fa 1
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2D ~
d. Explain why playing a sport and playing an instrument are not mutually exclusive events.
P(s pori: ) -4
jJ.
2.03
+
p(16S+.)
=/:. P (sport or inst)
~:;:f::.
1..310
203
203
2. At a school fair, a box contains 24 yellow balls and 76 red balls. One-fourth of the balls of each
color are labeled "win a prize".
Yellow Balls Red Balls
Total
a. Complete the two-way table.
Labeled "win a prize"
Not labeled
to
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25
,5
,(0
1lX)
2Y
Total
p(YellouJ/lP In)
~ ~.25
~5
. ;')
Find the probability that a ball is red and labeled "win a prize".
pC red 't- WI Yl
1£1
- .. 19
b. Find the probability that a ball labeled "win a prize" is yellow.
c.
100
d. Find the probability that a red ball is not labeled.
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p(nof lab ekd ) red)
5~1o:
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75
e. Find the probability that a ball is yellow or is not labeled.
)
p(yellow) + P(no+ Jabelecl)- p(Vet-NL.
;1.4
-t-. ~
18
=" 8 I
/00
100
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Give answers as fractions in simplest form.
3. Of the 148 students at an academic awards banquet, 40 won awards for mathematics, 82 won for
literature, and 12 won for both mathematics and literature.
a. Label a Venn Diagram that illustrates
the information.
b. One of the 148 students is chosen at random.
What is the probability that this student won an award
for mathematics or literature?
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reM}
p(L) - P M C\- L
+
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c. What
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~e prob~~ that a s{~nt ChOS~~ ~t raJ:tn did not win an award for mathematics?
J- f(w ,n fD r rY)£Lth)
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ID~,dg
,.
q.o _
~-
=:
13,
21
4. Test grades on an Algebra 2 Honors test were 9 As, 18 Bs, and 8 Cs.
a. The teacher randomly chooses 3 and removes 3 test papers from the class set. What is the
probability that she chooses tests with grades of A, B, and C in that order?
pee)
P(A)
pee)
t86~'
0,/05'
%:3
ZIb
==
6515
b. The teacher randomly chooses 3 test papers at the same time. What is the probability that
she chooses at least 2 tests with a grade of A?
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tp, \0
JA + I oth£r (p~ 3A
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+ a.0j 3
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_1\:3., '1-4J;C, + <3 C~
35 C.3
.
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5. Use the conditional probability formula
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=:
1020, _ \2.
b?L5
17
P(B IA) = p( AP(~) B) . Give the answer as a percent.
When a chemistry teacher gave two tests, 75% of the class passed both tests and 82% passed the
first test. To the nearest percent, what percent of those who passed the first test also passed the
f(2tJDll5f) =
second test?
P (boH1)
2e. 0.81
1b. 0.52
3b. 55/74
1c. 0.67
3c. 27/37
15 _
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9 ,
" 82
p (I.st)
Answers: 1a. 0.55
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2b. 0.24
4a. 216/6545
2c. 0.19
4b.
Qe~SQS
12./11
CC AIg2H P5 7-5 52015
2d. 0.75
5. 91 %