d = read.table("exmp11-10.txt",header=TRUE,sep=",")
d$Rail = as.factor(d$Rail)
fit = aov(time~Rail,data=d)
summary(fit)
MSTr = 1862.10
MSE = 16.17
I = 6
J = table(d$Rail)
n = sum(J)
sig2.A.hat = (MSTr-MSE)*(I-1)/(n-sum(J^2)/n)
print(sig2.A.hat)