You are part of a team at a mobile app company, tasked with improving user retention rates.
After collecting extensive user data, the team decides to use cluster analysis to understand patterns in user behavior and app interactions. Given the following scenarios, determine which would be appropriate applications of cluster analysis:
- Scenario I: Segmenting users based on their activity levels and feature usage to identify common characteristics of users who churn.
- Scenario II: Analyzing the average session time across all users to determine the most engaging aspects of the app.
- Scenario III: Grouping app features based on usage patterns to identify which are most associated with high user engagement.
- Scenario IV: Correlating marketing spend with user acquisition rates to optimize advertising strategies.
Choose the combination that accurately identifies the scenarios suited for cluster analysis.