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Question
Variance of the data 2, 4, 5, 6, 8, 17 is 23.33. Then variance of 4, 8, 10, 12, 16, 34 will be ______.
Options
23.23
25.33
46.66
93.32
Solution
Variance of the data 2, 4, 5, 6, 8, 17 is 23.33. Then, the variance of 4, 8, 10, 12, 16, and 34 will be 93.32.
Explanation:
Variance of 2, 4, 5, 6, 8, 17 is 23.33 = var (X) (say)
Using result:
If the variance of x1. x2 ....., xn is var (X)
Then the variance of ax1, ax2 ...... axn is a2 var (x)
Then variance of 4, 8, 10, 12, 16, 32
i.e 2(2), 2(4), 2(5), 2(6), 2(8), 2(17)
is (2)2 var (x)
= 22 × 23.33
= 4 × 23.33 = 93.32
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