$ $P(N)=0\mathrm{.}8$

$P(U)=0\mathrm{.}2$

$P(s_1|N)=0\mathrm{.}35$

$P(s_2|N)=0\mathrm{.}30$

$P(s_3|N)=0\mathrm{.}35$

$P(s_1|U)=0\mathrm{.}62$

$P(s_2|U)=0\mathrm{.}31$

$P(s_3|U)=0\mathrm{.}07$

$(a)$ Construct a decision tree for this problem.

$(b)$ What $is$ the recommended decision $if$ Martin does not wait until September?

blade attachment, $d_1$

new snowplow, $d_2(b)$ What $is$ the recommended decision $if$ Martin does not wait until September?

blade attachment, $d_1$

new snowplow, $d_2$$

What $is$ the expected value $(in$ $$)?$

$

$(c)$

What $is$ the expected value $(in$ $$)of$ perfect information?

$

$(d)$

What $is$ Martin's optimal decision strategy $if$ the decision $is$ not made until the September weather $is$ determined?

$If$ the weather $is$ normal, choose the

$---$Select$---$

$.Ifitis$ unseasonably cold, choose the

$---$Select$---$

$.$

What $is$ the expected value $(in$ $$)of$ this decision strategy?

$