Density and cumulative density

Basis van kansrekening in R

David Robinson

Chief Data Scientist, DataCamp

Simulating many outcomes

$$X \sim \text{Binomial}(10, .5)$$

$$\Pr(X=5)$$

flips <- rbinom(100000, 10, .5)

Basis van kansrekening in R

Finding density with simulation

flips <- rbinom(100000, 10, .5)
flips == 5
# [1] FALSE TRUE FALSE FALSE...
mean(flips == 5)
# [1] 0.2463

Basis van kansrekening in R

Calculating exact probability density

dbinom(5, 10, .5)
# [1] 0.2460938
dbinom(6, 10, .5)
# [1] 0.2050781
dbinom(10, 10, .5)
# [1] 0.0009765625
Basis van kansrekening in R

Cumulative density

$$X \sim \text{Binomial}(10, .5)$$

$$\Pr(X\leq 4)$$

flips <- rbinom(100000, 10, .5)
mean(flips <= 4)
# [1] 0.37682
pbinom(4, 10, .5)
# [1] 0.37695

Basis van kansrekening in R

Let's practice!

Basis van kansrekening in R

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