#cofidence interval for mean (p.2, ex.9)

#Data
vctr =c(11.1,12.5,13.6,9.1,8.7,10.6,12.5,15.6,13.8,8.0,10.9,7.6,5.2,1.2,12.8,16.7,13.9,10.1,9.6,10.8,11.6,12.3,12.9,11.6)

#Test for normality
shapiro.test(vctr)

#p value > 15 % and if p > 10%, then data from normal distributed(t-test)

#Find the mean
#m = mean(vctr)

#Construct the conf.interval (is usloviya 90% confidence interval)
t.test(vctr,conf.level=0.9)

#Hypothesis testing : H0:mu<=9 against Ha:mu>9
t.test(vctr,alternative="greater",mu=9)