A Poisson process describes the occurrences of an event in a given amount of time, area, volume, or other observation space. The rate of occurrence is the average number of times an event occurs per unit length of observation. In some cases, you may want to estimate the margin of error for the population rate using a specific sample size.

To estimate the margin of error obtained with a specific sample size for a Poisson rate, you must provide a rate planning value based on design specifications, expert opinions, or prior studies or small pilot studies.

The hospital researchers want to know the margin of error to estimate the daily rate of errors in all patient reports with a sample size of 300. The planning value rate is 0.15. With this sample size, the margin of error is 0.0507118 and - 0.0405890.