The range of scores is from 14 to 100 or 86, i.e., the difference between the lowest and the highest. Range is one measure of variability. Range was discussed above and is a crude measure of variability. The standard measure of spread or variability is the standard deviation. A large variance reflects a wide spread in the data.
Standard deviation measures the spread of from the mean.
Roughly speaking, it is the average distance of the data from the mean. Variance is simply the standard deviation squared. For example if the standard deviation is 2, the variance is 4. By using the square root of variance we avoid problems such as pounds squared or meters squared, etc. Hand held calculators and computer programs simplify the procedure of finding standard deviation and variance.