PrakKomstat_Pert4

#distribusi normal
#untuk P(X=x)
norm<-function(x,miu,sigma) {1/(sigma*sqrt(2*pi))*exp(-1/2*((x-miu)/sigma)^2)}
norm(750, 800, 50)

## [1] 0.004839414

dnorm(750, mean=800, sd=50)

## [1] 0.004839414

#distribusi eksponensial
#untuk P(X=15)
eks<-function(x,lambda){lambda*exp((-1)*lambda*x)}
eks(15,0.05)

## [1] 0.02361833

#untuk P(X<=15)
cdfexp <- function(x,lambda=0.05) {
  pdf<-function(t) {
    lambda*exp(-lambda*t)
  }
  hasil<-integrate(pdf,lower=0,upper=x)
  return(hasil$value)
}
cdfexp(15,0.05)

## [1] 0.5276334

#distribusi uniform, 
#untuk P(X=x)
uniform<-function(x, a=0, b=1) {1/(b-a)}
uniform(20, a=10, b=30)

## [1] 0.05

dunif(20, min=10, max=30)

## [1] 0.05