I'm a huge newbie when it comes to statistics and R.
I'm trying to make sense of all of these functions as someone who hasn't taken statistics before.
In R, from what I've understood, with dbinom, you enter the number of trails, the probability of success, and a number of successes n, all as arguments, and it returns the probability that the trail will succeed n times in a certain number of trails. Is this correct? dbinom is the probability density function, right?
As you can probably tell, there are a lot of things I'm confused about.
Firstly, can a probability density function only return a non-zero probability if the data is discrete?
pbinom is the cummumative version of the probability density function, correct? If the data is continuous, I would use the cumumlative function, right?
And now for the big question, what the hell is the difference between dbinom/pbinom and dnorm/pnorm?
From my understanding, pbinom gives you that probability that I first mentioned. You enter an number of successes, number of trails, and probability of succes, and it returns a probability. However, with dnorm, I don't understand what it is I enter. I know that I enter an x (which presumably also represents a number of successes), as well as a mean and a standard deviation. I also know that it does this for a normal distribution. What I don't understand is, why doesn't it ask for a probability, or a number of trails. Why does the x axis have negative values this time? What does it even return? Shoudn't it return 0 since presumably its not discrete? I know that it actually returns the calculation from the equation (the one with the standard deviation and mean), but I don't know what the equation really even represents.
Am I even making sense? I feel like I'm just spewing gibberish at this point.
Can someone set me on the right track, because I legitimately feel lost in all these terms, equations, and functions.
Any help is greatly appreciated. Thank you.