F-scale measurements 

Use the F-scale measurements of tornadoes listed in the accompanying table. The range of the data is 5.0. Use the range rule of thumb to estimate the value of the standard deviation. Compare the result to the actual standard deviation of the data, 1.2. Using the range rule of thumb, the standard deviation is approximately Compare the result to the actual standard deviation. The estimated standard deviation is V the actual standard deviation. Thus, the estimated standard deviation V substantially different from the actual standard deviation.