This paper presents an analysis of CitiBike data. It tests the hypothesis that people in their 30s are less likely than people in their 20s to use CitiBike for commuting. I obtained CitiBike data, cleaned the data, created visualizations to describe the data, and performed a statistical test on the data. In order to correctly use a statistical test, I reformulated my null hypothesis slightly, which I will explain further in the conclusion. My results obtained via the Chi-Square test for proportions showed that the proportion of people in their 20s using CitiBike for commuting is not independent of the proportion of people in their 30s using CitiBike for commuting.