00:01
All right, in your question, we have this probability mass function, pmf given to us, and we're asked to first find the range of the random variable.
00:09
The range is just the set of all possible values of that random variable, and that would be included over here.
00:17
So i just want to write 0 .2, 0 .4, comma, 0 .5, comma, 0 .8, and 1 .1.
00:30
So those are the possible values that x can take on.
00:36
Okay, so now part b we want to take the probability of x being less than or equal to 0 .5.
00:43
So in the chart, that would be everything probability -wise added up from here.
00:53
Okay, so this is your probability part of the question on this side.
01:00
Okay, so i'm just going to add these three values, which is going to do.
01:06
Be 0 .5.
01:11
Okay, the next question is we want to find the probability of being between 0 .25 and less than 0 .75.
01:21
So again, that's our random variable value.
01:24
So we want to be on the right side.
01:26
And i'm just thinking, okay, what x values do we have in our list that are between 0 .25 and 0 .75? that would be these two.
01:38
So we're only focused in this region, and we want to add these two probabilities...