You and frank examine the data you've collected. you discover that two main groups of people are buying healthy-food cookbooks: parents of small children and the elderly. what kind of unsupervised data mining technique are you and frank engaged in?

The fact that you and Frank examine the data you've collected and discover that two main groups of people are buying healthy-food cookbooks: parents of small children and the elderly means that you are using cluster analysis as a unsupervised data mining technique.

Cluster analysis sorts different objects into groups that are meaningful and useful in a way that the degree of association between two objects is maximal if they belong to the same group and minimal otherwise.

answer; /// i do believe that the above is (true)