This online course provides an in-depth understanding of confidence intervals and sample size, essential concepts in statistical inference. Students will learn how to construct and interpret confidence intervals for population parameters, including the mean and proportion, and understand the role of confidence levels in determining interval width. The course will cover the relationship between sample size and the precision of estimates, and how to calculate the required sample size for a desired confidence level and margin of error. Through interactive lessons, practical examples, and real-world applications, participants will gain the skills to make informed decisions based on sample data, ensuring their findings are both accurate and reliable.