Enter your data in the blue cells and the minimum sample size will be in the yellow cell at the bottom. Note: the standard deviation and E must be in the same units (e.g. inches, feet, etc). Download a copy of the workbook Min Sample Size for Mean CI V1.00
Although we normally start with the confidence level, C, we want for our confidence interval, sometimes you need to work backwards from the margin of error, E, and find the confidence level, In this problem, you are given some summary data about a survey and asked you to find the confidence level and the confidence …
Find Confidence Level, C, for Population Proportion Confidence Interval Read More »