data(ToothGrowth)
help(ToothGrowth)
ToothGrowth[1:10,]
summary(ToothGrowth)
len=ToothGrowth$len
supp=ToothGrowth$supp
dose=ToothGrowth$dose
summary(len[supp=="OJ"])
summary(len[supp=="VC"])
boxplot(len ~ supp)
par(mfrow=c(1,2))
hist(len[supp=="OJ"])
hist(len[supp=="VC"])
hist(len[supp=="VC"],freq=F)
lines(density(len[supp=="VC"]))
hist(len[supp=="OJ"],freq=F)
lines(density(len[supp=="OJ"]))
boxplot(len ~ dose)
summary(len[dose==0.5])
summary(len[dose==1])
summary(len[dose==2])
par(mfrow=c(2,2))
hist(len[dose==0.5])
hist(len[dose==1])
hist(len[dose==2])