The events in question are as follows.

E is the event that the value of your stock will double

F is the event that FDA will approve the "Clone-a-Sibling" kit

You are given that P(F) = 0.8. You also know that the probability of your stock doubling, given that the FDA approves the kit, is 0.95. This is P(E|F).

You are asked to find P(EF).

The definition

P(E|F)

=

P(EF) P(F)

can be used to find P(EF) if you solve for P(EF)

P(EF) = P(F)P(E|F) = (0.8)(0.95) = 0.76

Thus there is a 76% chance that the FDA will approve the product and the value of the stock you hold will double.