How to Interpret result of k-means clustering in R?

Machine Learning Clustering
#1

I performed K-means on a data-set. I have a question about some parameters that I got.

Results:

Sepal.Length Sepal.Width Petal.Length Petal.Width
1 5.006000 3.428000 1.462000 0.246000

In this case, what does “Cluster means” stands for?

I also get the following:

between_SS/total_SS = 90%

How can this value be interpreted?

#3

This is the sum of squared distances divided by the total squared error. The significance is the variance in the data. The ideal scenario is that most of the variance in the data is explained by the clusters, so you want this value to be high.