Find the variance of the numbers k, k+1, k+2,
-
A.
(frac{2}{3}) -
B.
1 -
C.
k + 1 -
D.
(k + 1)2
Correct Answer: Option A
Explanation
mean (x) = (frac{sum x}{N})
= k + k + 1 + k + 3
= (frac{3k + 3}{3})
= k + 1
(begin{array}{c|c} X & (X -X) & (X -X)^2\ hline k & -1 & 1 \ k + 1 & 0 & 0\ k + 2 & 1 \ hline & & 2end{array})
Variance (52) = (frac{sum (x – x)^2}{N})
= (frac{2}{3})