What is the mean deviation of x, 2x, x+1 and 3x. If their mean is 2?
-
A.
0.5 -
B.
1.0 -
C.
1.5 -
D.
2.0
Correct Answer: Option A
Explanation
| x | ∴x | x-X | /x-X/ |
| x | 1 | -1 | 1 |
| 2x | 2 | 0 | 0 |
| x+1 | 2 | 0 | 0 |
| 3x | 3 | 1 | 1 |
| ∑/x-X/=2 |
| Mean = | x+2x+x+1+3x |
| ____4 |
| 2 = | 7x+1 |
| _4 |
8 = 7x+1
7x = 8-1
7x = 7
x = 1
| Mean deviation = | ∑/x-X/ |
| __n |
| = | 2 |
| 4 |
| = | 1 |
| 2 |
= 0.5