As part of the quarterly reviews, the manager of a retail store analyzes the quality of customer service based on the periodic customer satisfaction ratings (on a scale of 1 to 10 with 1 = Poor and 10 = Excellent). To understand the level of service quality, which includes the waiting times of the customers in the checkout section, he collected the data shown below on 100 customers who visited the store.

Using the data given, apply k-means clustering with k = 5 using Wait Time (min), Purchase Amount ($), Customer Age, and Customer Satisfaction Rating as variables. Be sure to Normalize input data and specify 50 iterations and 10 random starts k-Means Clustering procedure. Analyze the resultant clusters.

What is the smallest cluster? What is the least dense cluster (as measured by the average distance in the cluster)? What reasons do you see for low customer satisfaction ratings?