What is the range rule of thumb?

Answer by  GrtPkn (7)

s approx = range/4 for example the standard deviation for the data set 5,8,8,9,10,12 and 13 is 2.7 and the range is 13-5 = 8 The range rule of thumb is s approx = to 2. This is an underestimate but close

Answer by  Anonymous

when referring to standard deviation, usual values are within two standard deviations of the mean.

Answer by  Brandon55 (1719)

When referring to measurement scores, you want a good range of scores to show differentiation of a test. If there is no range then there is no differentiation, which means the test is invalid or didn't work. The average score of tests should be around 80 to 85 percent. Keep in mind not all students will learn everything.

Answer by  patti (29325)

In measures of variance, the RROT says that range is roughly four times the standard deviation. So, the standard deviation is about one-quarter of the range. Therefore, most of the data will lie within two standard deviations of the mean.