IEE 380 Ch 3 Discrete pmf CDF

Chapter 3 of The Textbook has to do with discrete random variables um chapter four will be continuous random variables but the key word here is discrete and then we're going to talk about how to handle discrete probabilities for discrete random variables and learn about some probability distributions that have specific names um and have been you know fully explored

and have some nice equations so you're gonna you're gonna like that part of it for sure so what is a discrete random variable we have talked about this before so let me uh just remind you a random variable we say is a discrete random variable if it has a finite oh where that's going to bleed through

hang on a second here let's do it this way there we go if it has a finite number of values in a and then the other key word here is finite interval of its range so here's an example of how you can tell if a random variable is discrete or continuous just look at the range so the random variable

X if it's a face value for the throw of a fair die we could certainly say this is the range right it would be we can throw well one can come up a two a three a four a five or a six so we can see that the range I just just wrote it down

the range of X is one two three four five and six and a finite interval of its range what if I just said oh let's go 2 up to four well how many values are in there well there are three values in there three values we have two three and four so three

values finite number of values in a finite interval of its range and so therefore X is a discrete random variable here's another example suppose that I have three cameras and I'm going to um I'm going to inspect them and I'm going to say that they either pass or they fail the test okay