1. Short Answer. Of 23 college sophomores at Crocodile Community College, 12
preferred pepperoni pizza, 7 preferred supreme, and 4 preferred cheese. If we
picked a college sophomore at Crocodile Community College at random, what is
the probability that he or she would prefer cheese? Give solution exactly in
reduced fraction form.
Probability the student prefers cheese =
0
1157833983
Short
number of students who prefer cheese
total number of students
4
= 23
1
2. If the probability of seeing moose in a day in a certain region of Alaska
is 0.81, what is the probability of not seeing any moose in a day there?
0.81
1.19
the probability of the complementary event =1-0.63=0.37
0.19
-0.81
0
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MultipleChoice
7
3. If the odds of winning a raffle are 12:258, what is the probability of
winning?
12/270
probability of winning = odds of winning/(total odds)
12/258
258/270
258/12
0
1157833985
MultipleChoice
15
4. Essay. According to the U. S. Census Bureau, the total 2008 U.S. population
was 303,824,640. The chart below summarizes the 2008 population for five U.S.
States.
U. S. State
Missouri
Pennsylvania
Tennessee
Utah
Washington
2008
Population
5,911,605
12,448,279
6,214,888
2,736,424
6,549,224
SOURCE: U. S. Census Bureau
What is the probability that a randomly selected U.S. resident did not live
in Missouri? Show step by step work. Round solution to the nearest
thousandth.
Compute first the total number of residents who lived in these 5 states:
=33,860,420
5,911,605
Then compute the probability a random US resident lives in Missouri = 33,860,420 = 17.46%
It follows that
the probability a random US resident did not live in Missouri is = 1 − 17.46% = 𝟖𝟐. 𝟓𝟒%
0
1157833986
Essay
6
5. Essay; show all work. A simple dartboard has three areas… the main board
has a radius of 10 inches, there is a circle with a radius of 5 inches, and
the bullseye has a radius of 2 inches. What is the probability of a random
dart landing inside the bullseye?
Round to the nearest thousandth. (Hint: Use A=r^2)
Total area of the target = 𝜋 × 102 = 100𝜋
Area of the bulls-eye =𝜋 × 22 = 4𝜋
4𝜋
𝟏
Probability a random dart lands inside the bulls-eye = 100𝜋 = 𝟐𝟓 = 𝟒%
0
1157833987
Essay
12
6. A certain drawing states that the odds of winning are 326:131. What would
be the odds against winning?
326:131
131:326
326:457
131:457
0
1157833988
MultipleChoice
23
7. Essay; show all work. The property restoration company PuroServ is
considering switching to new dehumidifiers. Their market research,
considering the cost of the new machines and their efficiency, tells them
that the switch would give them an 80% chance of making a $20,000 profit, a
15% chance of breaking even, and a 5% chance of losing $5,000. How much money
does PuroServ expect to make with their new purchase?
Expected Profit= 0.80 × 20000 + 0.15 × 0 + 0.05 × (−5000) = $𝟏𝟓, 𝟕𝟓𝟎
0
1157833989
Essay
21
8. Essay; show all work. Last fall, a gardener planted 55 iris bulbs. She
found that only 45 of the bulbs bloomed in the spring.

Find the empirical probability that an iris bulb of this type will
bloom. Give answer as a fraction in lowest terms.
the empirical probability that an iris bulb of this type will bloom is 45/55
=9/11

How many of the bulbs should she plant next fall if she would like at
least 51 to bloom?
Let x be the number the bulbs she should plant if she
wants at least 53 to bloom.
51
𝑥
≤
9
11
→𝑥≥
11×51
9
= 62.33 → 𝑥 = 63
At least 63 bulbs should be planted.
0
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Essay
40
9. Essay; show all work. A community 5K run will award $50 to the winner. 65
people enter the race, and they each pay an entry fee of $20. Assuming they
are all equally likely to win, what is a fair price for the competition?
Round to the nearest cent.
65 people contribute $20 each. Since only one prize is awarded a
fair first prize would be
65 × 20 = $𝟏𝟑𝟎𝟎.
Since the first prize is only $50 it is likely the organizers
are pocketing the difference of $1,250.