The goal is to group these objects into k=2 group of medicine based on the two features (pH and weight index).

K = 2

1] Obtain adjacency matrix.

2] Let $c_1$ = {A} & $c_2$ = {B}

$\therefore$ centroid of $c_1$ = {A} = { (1,1) }

" $c_2$ = {B} = { (2,1)}

3] $c_1$ = {A}

$c_2$ = { B, C, D}

$\therefore$ centroid of $c_1$ = {(1,1)}

" $c_2$ {( $\frac{2+4+5}{3}, \frac{1+3+4}{3} )$}

= {(3.67, 2.67)}

3] $c_1$ = {A , B}

$c_2$ = {C , D}

$\therefore$ centroid of $c_1$ = { (1.5, 1)}

" $c_2$ = {(4.5, 3.5)}

$\therefore$ $c_1$ = {A, B}

$c_2$ = { C, D}

$\because$ there is no change, these are the final clusters.