Psychological Assessment
(Average Deviation)
Instructions: Compute the value of the average deviation of the frequency distribution
Steps to follow to apply the formula of Average Deviation for grouped data:
1. Compute the value of the mean
2. Get the deviation by using the expressions ๐ฅ -๐ฅ๎ชง
3. Multiply the deviation by its corresponding frequency
4. Add the results in step 3
5. Divide the sum in step 4 by n.
Formula: ๐จ๐ซ =โ๐|๐โ๐
๏ฅ|
๐
Given: Classes Interval, frequency
Classes Interval
๐
Midpoint
(๐)
๐๐
11-22
3
16.5
49.5
23-34
5
28.5
142.5
35-46
11
40.5
445.5
47-58
19
52.5
997.5
59-70
14
64.5
903
71-82
6
76.5
459
83-94
2
88.5
177
n=60
โ๐๐ = ๐, ๐๐๐
Step 1: Compute the value of the mean
Solve the Mean (๐
๏ฅ) by using its formula:
๐ฅ๎ชง = โ๐๐ฅ
๐
๐ฅ๎ชง = 3,174
60
๐
๏ฅ=๐๐. ๐
Step 2: Get the deviation by using the expressions ๐ฅ -๐ฅ๎ชง
๐โ๐
๏ฅ
|๐ โ ๐
๏ฅ|
-36.4
36.4
-24.4
24.4
-12.4
12.4
-0.4
0.4
11.6
11.6
23.6
23.6
35.6
35.6
