
76 Decision Based Design
standard deviation of $5. There is uncertainty about the mean of the out-
comes, and it is believed that it is distributed uniformly between $45 and
$60. The utility function of the decision maker is again given by
=
0.8
Ux x
.
The expected utility before consulting John is given by
∫∫
[]
=
−∞
()
;,5
15
0.8
2
45
60
EUxx
fxt
dtdx
T
N
(3.16)
The expected utility value of the uncertain node is calculated numerically
and found to be equal to 23.78, which is greater than the utility for $50, which
is 22.86. Therefore, before the information is acquired, the decision maker pre-
fers the lottery. The decision maker consults John again, who ...