PRAK-4-KOMSTAT.R

#1
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,       # yang ditanya
      mean=800,  # rata-rata
      sd=50)     # standar deviasi

## [1] 0.004839414

#2
eks<-function(x,lambda){lambda*exp((-1)*lambda*x)}
eks(15,0.05)

## [1] 0.02361833

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

#3
uniform<-function(x,a=0,b=1){
  ifelse(x>=a & x<=b, 1/(b-a), 0)
}
uniform(20,a=10,b=30)

## [1] 0.05

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

## [1] 0.05

#POST TEST
#1
eks<-function(x, lambda =1/6){lambda*exp((-1)*lambda*x)}
eks(4)

## [1] 0.08556952

cdfexp<-function(x, lambda =1/6){
  pdf<-function(t){
    lambda*exp(-lambda*t)
  }
  hasil<-integrate(pdf, lower=0, upper=x)
  return(hasil$value)
}
cdfexp(4)

## [1] 0.4865829

#2
uniform<-function(x,a=0,b=1){
  ifelse(x>=a & x<=b, 1/(b-a), 0)
}
uniform(6,a=2,b=10)

## [1] 0.125

dunif(6,min=2,max=10)

## [1] 0.125