# Set random seed. Don't remove this line.
set.seed(100)
# Explore the structure of your data
str(school_result)
# Initialise ratio_ss
ratio_ss<-rep(0,7)
# Finish the for-loop.
for (k in 1:7) {
# Apply k-means to school_result: school_km
school_km<-kmeans(school_result,k,nstart=20)
# Save the ratio between of WSS to TSS in kth element of ratio_ss
ratio_ss[k]<-school_km$tot.withinss/school_km$totss
}
# Make a scree plot with type "b" and xlab "k"
plot(ratio_ss,type="b",xlab="k")