when do i use standard error why use std dev or sem in an experiment when is standard error used in an experiment can std error be used for mean arithmetic when should standard error be used what is the difference between std and sem when to use standard error on the mean which statement best describes a study where the std dev is the only method of estimating a mean? why use sem in an experiment when to use standard error on mean when to use sem or sm difference between std and sem what is the standard error of a measurement when to use standard error on the data when is sam or sm used when does the standard error use the mean why is std used vs standard error why use standard error and std when to use the standard error when to use the standard error on the sm