This table below gives the scores of a group of students in a Further Mathematics Test.
Score
1
2
3
4
5
6
7
Frequency
4
6
8
4
10
6
2
Calculate the mean deviation for the distribution
A
4.32
B
2.81
C
1.51
D
3.90
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Score(x)
1
2
3
4
5
6
7
Total
Frequency (f)
4
6
8
4
10
6
2
40
fx
4
12
24
16
50
36
14
156
x - \(\bar{x}\)
-2.9
-1.9
-0.9
0.1
1.1
2.1
3.1
|x - \(\bar{x}\)|
2.9
1.9
0.9
0.1
1.1
2.1
3.1
f|x - \(\bar{x}\)|
11.6
11.4
7.2
0.4
11
12.6
6.2
60.4
Mean = \(\frac{\sum fx}{\sum f}\)
= \(\frac{156}{40}\)
= 3.9
M.D = \(\frac{\sum f|x - \bar{x}|}{\sum f}\)
= \(\frac{60.4}{40}\)
= 1.51
Source: Myschool Past Questions Archive (Record #55378)