In this section, we will introduce the formula for a confidence interval for a mean when the population standard deviation is known. This case is only used for one real purpose, and that is to calculate the sample size necessary for a given margin of error. Two examples are included that involve finding the required sample size.
In this video, we introduce the t-distribution and why it is necessary to use the t-distribution to find a confidence interval for a mean. We also look at the t-table in detail.
Checking the conditions for a t-interval and the calculation of one example t-interval.