SECTION 14.3 Measures of Disbursement

Objective  Determine the spread of a data set.

Key Terms: 1. Range: the difference between the largest and the smallest data values in the set. 2. Standard Deviation: a measure based on calculating the distance of each data value from the mean.

Computing the Standard Deviation  To compute the standard deviation for a sample consisting of n data values, do the following: 1. Find Χ 2. Compute Deviation: (X – Χ ) 3. Compute (Deviation) 2 4. Compute s Data ValuesDeviation(Deviation) 2

Computing the Sample Standard Deviation for a Frequency Distribution  To compute the sample standard deviation for a frequency distribution consisting of n data values, do the following: 1. Find Χ 2. Compute Deviation: (X – Χ ) 3. Compute (Deviation) 2 … Σ columns 2, 3, and Compute s xfx fdev.(dev.) 2 (dev.) 2 f

Example 1:  Find the range, mean, and standard deviation for the following data set.  TB pg. 814/1

Example 2:  TB pg. 814/5

Example 3: Calculate s for a frequency distribution.  TB pg. 814/ 11 xfx fdev.(dev.) 2 (dev.) 2 f Σ

Example 4: Calculate s for a frequency distribution.  TB pg. 814/15 xfx fdev.(dev.) 2 (dev.) 2 f Σ

Example 5: Find the mean and standard deviation.  TB pg. 815/19

Example 6: Find the mean and standard deviation.  TB pg. 816/21 xfx fdev.(dev.) 2 (dev.) 2 f Σ

Key Concept:  Calculate number of s from x.  Formula:

Example 7: Calculate number of standard deviation from mean.  TB pg. 816/27

Example 8: Calculate number of standard deviation from mean.  TB pg. 817/29

Key Concept:  Calculating coefficient variable.  CV =

Example 9: Calculate coefficient variable.  TB pg. 817/31

Example 10: Calculate coefficient variable.  TB pg. 817/33

Example 11: Calculate coefficient variable.  TB pg. 817/37

Section 14.3 Assignment  Class work:  TB pg. 814/2 – 22 Even, and 28 – 38 Even Please remember to write problems and show work. This assignment is due Mon., 12/19/11. THIS ASSIGNMENT WILL NOT BE ACCEPTED LATE!!!