This preview shows pages 1–6. Sign up to view the full content.
10/6/09
Lecture 10
1
STOR 155 Introductory Statistics
Lecture 10: Randomness and
Probability Model
The
UNIVERSITY
of
NORTH CAROLINA
at
CHAPEL HILL
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document 10/6/09
Lecture 10
2
•
Let’s Make A Deal
: a game show back in the 90’s.
•
A player is given the choice of three doors. Behind one door is
the Grand Prize (a car and a cruise); behind the other two
doors, booby prizes (stinking pigs). The player picks a door,
and the host peeks behind the doors and opens one of the
rest of the doors. There is a booby prize behind the open
door.
•
The host offers the player either to stay with the door that was
chosen at the beginning, or to switch to the remaining closed
door.
•
Which is better: to switch doors or to stay with the original
choice? What are the chances of winning in either case?
The Monty Hall Problem
10/6/09
Lecture 10
3
• Three prisoners,
A, B
, and
C
are on death row. The
governor decides to pardon one of the three and
chooses at random the prisoner to pardon.
• He informs the warden of his choice but requests
that the name be kept secret for a few days.
• The next day,
A
tries to get the warden to tell him
who had been pardoned.
• The warden refuses.
A
then asks which of
B
or
C
will
be executed. The warden thinks for a while, then tells
A
that
B
is to be executed.
• Can
A
increase his chance of survival by swapping
his fate with
C
?
3 Prisoners’ Dilemma
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document 10/6/09
Lecture 10
4
• The previous two problems are equivalent.
• Play it online at
–
http://www.shodor.org/interactivate/activities/mont
y3/
• How can we solve similar problems
systematically?
– Probability models
Remarks
10/6/09
Lecture 10
5
• We call a phenomenon (or an experiment)
random
if individual outcomes are uncertain, but
a regular distribution of outcomes emerges with
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 11/17/2011 for the course STOR 155 taught by Professor Andrewb.nobel during the Fall '08 term at UNC.
 Fall '08
 AndrewB.Nobel

Click to edit the document details