{

#test=matrix(scan("hel34"),ncol=2,byrow=T)

xx=scan("hel55")

# Confidence interval on the population mean
# assuming the data is Normally distributed

print(c(t.test(x)$conf.int))

#or

alpha=0.05		#confidence level
alpha2=alpha/2

N=length(xx)
#Lower limit
XL = mean(xx) - qt(alpha2,N-1)*sd(xx)/sqrt(N)

#Upper Limit
UL = mean(xx) + qt(1-alpha2,N-1)*sd(xx)/sqrt(N)

print(c(XL, UL))
#############

#confidence interval on the population variance

#Lower Limit
VL = var(xx)*(N-1)/qchisq(1-alpha2,N-1)

#Upper Limit
UL = var(xx)*(N-1)/qchisq(alpha2,N-1)

print(c(XL, UL))
###########


#confidence interval on the median..
xx=sort(xx)

xl=qbinom(0.025,length(x),0.5)
xu=qbinom(0.0975,length(x),0.5)

print(c(xx[xl],xx[xu]))

}