## Elementary Statistics: A Step-by-Step Approach with Formula Card 9th Edition

range=62 $s^2=332.4$ $s=18.2$ $s'=15.5$ The estimate is less than the actual standard deviation.
range=max-min=62 variance=332.4 (use definition formula) standard deviation=18.2 (square root of variance) Use the range rule of thumb to estimate the standard deviation. $s'=\frac{range}{4}=15.5$ The estimate is less than the actual standard deviation.