00:01
For this question, we are given the probability distribution shown in this table for a discrete random variable x, and for part a we were asked if this is a valid probability distribution.
00:14
Now in order to be valid, all of the probability masses must be between 0 and 1, and that is the case they are, and the other thing is that the summation of all of the probability masses must be 1.
00:48
And if we add up these four numbers, they do come out to 1.
00:55
And so the answer for a is yes.
00:57
It says the probabilities add up to 1.
01:06
And then for b, we are asked, what is the probability that the random variable x is less than 38? now there exist three outcomes where x is less than 38, 15, 22, and 34.
01:23
So the probability that x is less than 38 is the probability...