Find the variance of 2x, 2x-1 and 2x+1
A
2/3
B
2
C
√(2/3)
D
1
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
\(\sum x = 6x\)
\(\sum(x-\bar{x})^2\) = 2
\(\bar{x} = \frac{\sum x}{n}\)
= \(\frac{6x}{3}\)
= 2x
Variance = \(\frac{\sum(x-\bar{x})^2}{n}\)
= \(\frac{2}{3}\)
Source: Myschool Past Questions Archive (Record #8663)