# Step 2 using R:
lm0	<- lm(ym ~ grp, data = dt, weights = wght)
sd0	<- summary(lm0)$sigma
sc	<- sqrt(36)/sd0
Fvalue	<- anova(lm0)[“grp”,“F value”]/(sc*sc) # Rescale F stat
# Step 3
alpha	<- 0.05
n	<- 50
ni	<- 6
P	<- 2
numdf	<- 1
dendf0	<- n*ni − n
qF	<- qf(1−alpha, numdf,dendf0)
dendfA	<- n*ni − p
(power	<- 1− pf(qF,numdf,dendfA, numdf*Fvalue))
[1] 0.7436023