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Math 381 Probability
& Statistics I
Name:
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EXAM 1 Fall 2005 RWJ
Instructions:
.
One page of notes and calculator allowed (but nothing else)
.
Please show work/reasoning
for (partial) credit
.
Read questions carefully
.
Note point values on questions
.
If you have extra time, check over answers
before turning in your exam
.
Note any writing on the blackboard pertaining
to the exam
.
Good
luck!
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5.
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6.
/ 7
/103 (maximum score of 100
is possible)
)
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1. (30 pts.) Your instructor played on a softball team this past summer where we played
two games each night we played. Suppose
that we won the first game 35% of the time
(i.e. a probability of 0.35), the second game 75% of the time, and both games 25% of the
time.
Determine each of the following:
a. The chance we won at least one game.
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b. The chance we won only the first game
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c. The chance we won exactly one game
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d. The chance we won the second game given we won the first game.
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2. (22 pts.) In the Minnesota "Gopher 5" Lottery one chooses 5 numbers
from the field 1
through 47. The game costs $1 to play. Here is a table of an individual's (gross) winnings
by the number of matches
they have:
Number of Matches
Winnings
...
.
T1.1
5 of 5 numbers
Jackpot
(starts at $100,000)
4 of 5 numbers
$500
3 of 5 numbers
$15
2 of 5 numbers
$1
a. What is the chance of winning the Jackpot
in a single play? Express your answer
in
terms of binomial coefficient(s).

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b. What is the chance of winning $15 (i.e. that you have net winnings of $14)? Express
your answer
in terms of binomial coefficient(s).
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This homework help was uploaded on 01/21/2008 for the course MATH 381 taught by Professor Johnson during the Fall '04 term at SDSMT.
 Fall '04
 JOHNSON
 Statistics, Probability

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