$5.$ the reservatio price of design a is

$6.$ the reservation price of design b is

$7.$ Suppose, instead of having to test exactly one design $($as in Q$3$ and Q$4),$ you decided to undertake sequential testing. That is$,$ you can test one alternative and then test the second alternative if you need to$.$ Which alternative should you test first?

a$.$ design a

b$.$ design b

$8.$ Using a decision$-$tree, find the expected value from testing A and then testing B $($if needed$)$

$9.$ Using a decision$-$tree, find the expected value from testing B and then testing A $($if needed$)$