In what proportion of cases will the mean of a sample selected by EPSEM be more than ±3 Z scores from the population mean?
A) less than 1%
B) between 3% and 5%
C) between 85% and 90%
D) between 95% and 99%

Question

Quizplus · Accepted Answer

In a normal distribution, approximately 99.7% of data falls within ±3 Z scores from the mean, leaving less than 1% of data beyond this range.

In What Proportion of Cases Will the Mean of a Sample