I currently conduct research on factors that influence career choice and I decided to use 0.1 as the margin of error. My supervisor asks me to explain the reason the value is selected. What reason or example can I provide??
There are multiple methods to calculate margins of error by using the standard deviation and other statistical values you can obtain from your data. You can easily find them by looking up how to calculate the margin of error in a data set.
Calculating it this way is much more safe and consistent with standards than trying to provide an estimated margin of error. You can also explain how you got to the value much easier to your supervisor.