1. Thinking Mathematically Statistics: 12.3 Measures of Dispersion

2. The Range The range, the difference between the highest and lowest data values in a data set, indicates the total spread of the data. Range = highest data value - lowest data value Exercise Set 12.3 #5 Find the range for 3, 3, 4, 4, 5, 5

3. Computing the Standard Deviation for a Data Set 1.Find the mean of the data items. 2.Find the deviation of each data item from the mean: data item - mean 3.Square each deviation: (data item - mean) 2 4.Sum the squared deviations: add up all of the (data item - mean) 2

4. Computing the Standard Deviation for a Data Set cont. 5.Divide the sum in step 4 by n-1, where n represents the number of data item. 6.Take the square root of the quotient in step 5. This value is the standard deviation for the data set. Standard deviation =

5. Example Standard Deviation Exercise Set 12.3 #17 Find the standard deviation for 1, 2, 3, 4, 5

6. Thinking Mathematically Statistics: 12.3 Measures of Dispersion