Statisticians have determined that values no greater than plus or minus 2 SD represent measurements that are more closely near the true value than those that fall in the area greater than ± 2SD. Thus, most QC programs call for action should data routinely fall outside of the ±2SD range.
Is 5 a high standard deviation?
5 = Very Good, 4 = Good, 3 = Average, 2 = Poor, 1 = Very Poor, The mean score is 2.8 and the standard deviation is 0.54.
What does standard deviation tell you about test scores?
Standard deviation tells you, on average, how far off most peoples scores were from the average (or mean) score. If the standard deviation of a set of scores is low, that means most students get close to the average score (in this case, 1051).
What is mean absolute deviation used for in real life?
Mean absolute deviation is the average distance between the mean of a set of numbers. This is used to analyze statistics in many fields. Find the mean of those numbers in order to determine the average distance between each data number and the mean.