The Total solution for NCERT class 6-12
Xi
Deviations from mean
(xi – x̅)
(xi – x̅)2
6
6 – 9 = -3
9
7
7 – 9 = -2
4
10
10 – 9 = 1
1
12
12 – 9 = 3
13
13 – 9 = 4
16
4 – 9 = – 5
25
8
8 – 9 = – 1
74
We know that Variance,
σ2 =(1/8) × 74
= 9.2
∴Mean = 9 and Variance= 9.25