Upcoming SlideShare
×

# Measure of Dispersion

1,582 views

Published on

Published in: Education, Technology
0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total views
1,582
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
74
0
Likes
0
Embeds 0
No embeds

No notes for slide

### Measure of Dispersion

1. 1. 12.3 Measures of Dispersion<br />
2. 2. Range<br />The difference between the highest and lowest data values<br />Range = highest – lowest<br />
3. 3. Example 1<br />Find the range for a set of data:<br />A. 10, 20, 30, 40, 50<br />B. 84, 30, 90, 59, 67, 29<br />
4. 4. Standard Deviation<br />Dependent on all of the data items<br />Found by determining how each value deviates (or differs) from the mean<br />
5. 5. Computing the standard deviation for a data set<br />1. Find the mean of the data items.<br />2. Find the deviation of each data from the mean<br /> data item – mean<br />3. Square each deviation<br /> (data item – mean) 2<br />4. Sum the squared deviations<br /> ∑ (data item – mean) 2<br />
6. 6. Cont…<br />5. Divide the sum by n-1 where n represents the number of items.<br />∑ (data item – mean) 2<br /> n-1<br />6. Take the square root of the answer.<br /> √ ∑ (data item – mean) 2<br />n-1<br />