Abstract
The topic is about how the young generation (age under 35) use Citibike. If it different in terms of gender or time? I make a hypothesis that young women more likely to use Citibike compare to young men. For the purpose of statistic testing. I create my hull hypothesis as  The fraction of young women ( age under 35) riding on the weekend of all young women biking on any day of the week are less or equal to the proportion of young men (age under 35) on the weekends of all young men biking on any day of the week.  For the data collection, I use Citibike API for the month of Feb 2015 with around 196930 rows of data. Based on the review from Professor Bianco, I use both the Z test and Chi-square test for my null hypothesis to compare the two group of data and the results help my reject my null hypothesis.  My conclusion is young women,  compare to young men, are more likely to use Citibike on the weekend.