Question

Need help with R coding

x <- matrix(rnorm(2000, 20, 5),nrow=100)
xbar20 <- rowMeans(x)
UL <- xbar20+qnorm(.90)*5/sqrt(20)
LL <- xbar20-qnorm(.90)*5/sqrt(20)
cover<-sum(UL>20 & LL<20)/100

this code finds coverage for an 80% confidence interval

change code to use beta distribution with ( shape1=5,
shape2=1).

theoretical parameter values are: ? = 0.83, ? = 0.14

Answer 1

Answer

The R code for finding coverage for an 80% confidence interval change code to use beta distribution with ( shape1=5,
shape2=1) is

x <- matrix(rbeta(2000, shape1=5,shape2=1),nrow=100)
xbar20 <- rowMeans(x)
UL <- xbar20+qnorm(.90)*0.14/sqrt(20)
LL <- xbar20-qnorm(.90)*0.14/sqrt(20)
cover<-sum(UL>0.83 & LL<0.83)/100

Note : Output is changes every time you run the code so for fixing the output of the R code, one should use seed() function.