Mathematics for Computer Science

Chapter 18 Random Variables760

you guess

right?

Eric guesses

right?

no

yes

no

yes

1=2

1=2

1=2

1=2

1=2

1=2

yes 0

no 1

yes 1

no 0

yes 0

no 1

yes 1

no 0

yes

no

your

payoff

$0

$1

$1

$4

�$2

�$2

�$2

$0

probability

0

1=4

1=4

0

0

1=4

1=4

0

Nick guesses

right?

Figure 18.7 The revised tree diagram reflecting the scenario where Nick always
guesses the opposite of Eric.