Question

If a denotes some​ event, what does upper a overbar ​denote? if ​p(a)equals0.995​, what is the value of ​p(upper a overbar​)? if ​p(a)equals0.995​, is upper a overbar ​unlikely?

Answer 1

$P(A)=0.995\\P(A')=0.005$

So $P(A')$ is pretty much unlikely.