pbinom function
This function returns the value of the cumulative density function (cdf) of the binomial distribution given a certain random variable q, number of trials (size), and probability of success on each trial (prob).
Syntax: pbinom(x, size, prob)
Parameters:
- x: a vector of numbers.
- size: the number of trials.
- prob: the probability of success of each trial.
pbinom function returns the area to the left of a given value q in the binomial distribution. If you’re interested in the area to the right of a given value q, you can simply add the argument lower.tail = FALSE
Syntax:
pbinom(q, size, prob, lower.tail = FALSE)
Example 1:
Under this example, we are calculating the probability to get a head more than 3 times if the coin is flipped fairly 10 times using the pbinom() function. Since the coin is tossed fairly the prob parameter to the function is passed to be 0.5.
R
pbinom (3, size=10, prob=.5, lower.tail= FALSE ) |
Output:
[1] 0.828125
Example 2:
In this example, we are calculating the probability if a man scores a strike on 30% of his attempts when he bowls, If he bowls 50 times, what is the probability that he scores 30 or fewer strikes using the pbinom() function in R.
R
pbinom (30, size=50, prob=.7) |
Output:
[1] 0.0848026
A Guide to dbinom, pbinom, qbinom, and rbinom in R
In this article, we will be looking at a guide to the dbinom, pbinom, qbinom, and rbinom methods of the binomial distribution in the R programming language.