Consider below sample data and apply K$-$Means clustering. Take subjects $1$ and $4$ as initial cluster centres and then identify the cluster centres after two iterations. Find out the first and second iteration cluster centres. Choose the Manhattan distance as distance measure.

Subject A B

$11\mathrm{.}01\mathrm{.}0$

$21\mathrm{.}52\mathrm{.}0$

$33\mathrm{.}04\mathrm{.}0$

$45\mathrm{.}07\mathrm{.}0$

$53\mathrm{.}55\mathrm{.}0$

$64\mathrm{.}55\mathrm{.}0$

$73\mathrm{.}54\mathrm{.}5$

$($b$)$ Illustrate the strength and weakness of k$-$means in comparison with k$-$medoids.

$($c$)$ Illustrate the strength and weakness of these schemes in comparison with a hierarchical clustering scheme $($e$.$g$.,$ AGNES$)$