Then x obeys the normal distribution N(8.9)

Then p (x > 5) = p (5 < x ≤ 8)+p (x > 8).

= 1/2P(5 < X≤ 1 1)+P(X > 8)

= 1/2*0.6826+P(X>8)

=0.34 13+0.5

=0.84 13

Let the profit of scheme 2 be y,

Then y obeys the normal distribution N(3.4)

Then p (x > 5) = p (x > 3)-p (3 < x ≤ 5).

=P(X>3)- 1/2P( 1