small<-c(41,45,42,62,68,54,52,55,44,60)
large<-c(74,74,70,52,76,91,71,78,76,78,83,50,52,66,65,53,72)

(mean(small))
(mean(large))

(vs<-var(small))
(vl<-var(large))

(fc<-vl/vs)
(pfc<-pf(fc, df1=16, df2=9,lower.tail=F))

var.test(large, small, alternative="greater", conf.level=0.95)
(f<-qf(0.05, df1=16, df2=9, lower.tail=F))

var.test(large, small, alternative="two.sided", conf.level=0.95)
(f1<-qf(0.025, df1=16, df2=9, lower.tail=F))
(f2<-qf(0.975, df1=16, df2=9, lower.tail=F))

(lower_bound<-fc/f1)
(upper_bound<-fc/f2)

(f<-qf(0.05, df1=16, df2=9, lower.tail=F))

library(sjPlot)
par(mfrow=c(2,1))
dist_f(p=0.05, deg.f1 = 16, deg.f2 = 9, xmax=8)
dist_f(f=1.627159, deg.f1 = 16, deg.f2 = 9, xmax=8)