To get the required value of the missing probability to
make the series complete is to deduct all the probability given to 1 because we
know that the discrete probability distribution must be equal to 1. So doing
what I have said, this will be:
P(4) = 1 - P(3) - P(5) - P(6)
= 1 – 0.3 – 0.18 – 0.21
= 0.31 is the answer.
