ANSWER
i think it is six.
EXPLANATION
-300>100 that is the answer because its below sea level
Answer with Step-by-step explanation:
We are given that
P(A)=0.4 and P(B)=0.7
We know that

We know that
Maximum value of
=1 and minimum value of
=0






It is not possible that
is equal to 1.1


Multiply by (-1) on both sides

Again, 



Multiply by (-1) on both sides

Hence, 
The best estimate is probably 4