Following is the normalized distance matrix of sales data for four customers of a company. Apply single linkage clustering until only one option remains. Draw a dendogram illustrating the clustering process. What conclusions can you draw from this analysis for this company?

Customer	1	2	3	4
1	0	3.88382	2.08990	2.70886
2		0	3.21080	1.97620
3			0	2.99488
4				0