This is personal study note Copyright and original reference: https://www.youtube.com/watch?v=bSrelzpmpbA&list=PLsri7w6p16vulKaxOlNQFSWuyDuE9oEVP&index=5&t=5s ================================================================================ ================================================================================ ================================================================================ Population ratio: - confidence interval of sample ratio $$$\hat{p}$$$ Sample ratio $$$\hat{p}$$$ - when you extract sample data - you get the ratio of $$$\frac{t}{n}$$$ $$$\dfrac{\text{specific event}}{\text{number of sample}}$$$ And "confidence interval" on "sample ratio" is "population ratio" ================================================================================ Example ================================================================================ How to decide number of sample ================================================================================ Example