Use the following description for Questions $1-2.$

Assume there are $4$ customers $($Kristen$,$ Dennis, Ben and Ross$),$ and we want to develop a hierarchical clustering

model to group the customers into clusters. The input variables used in this clustering model to calculate the

distance values are: how much the individual spent for grocery shopping in winter $2020($measured in $$)$ and how

much the individual spent for grocery shopping in summer $2020($measured in $$).$

Euclidean distance values $($measured in $$)$ between all pairs of customers are given in Table $1$ below. For example,

the Euclidean distance between Dennis and Ben is $$360.$

Table $1.$

Distance values between all customer pairs

Question $1.$ Based on the distance values in Table $1,$ the first cluster in a hierarchical clustering model will include:

Kristen and Dennis

Dennis and Ben

Dennis and Ross

Ben and Ross