1. Please give the method of RPI estimation of 180 days (for example, if 10,000 people are installed today, the accumulated game recharge of 10,000 people will be $100,000 in the next 180 days (including today), and the RPI of 180 days for 10,000 people installed today = 100,000/10,000).(RPI: Revenue per install.180-day RPI refers to the accumulative recharge per capita from the user's installation to the 180th day)

2. 2. In order to test the 180-day RPI of a game product, how many installed users are required to complete the test?(If it can be calculated, please give the calculation process and results.If not, please give the reason why not.)