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Let 1x(1),x(2)….x(n) be n obervations .L...

Let 1`x_(1),x_(2)….x_(n)` be n obervations .Let `w_(i)=lx_(i) +k " for " i=1,2….n,`where l and k are constants. If the mean of `x_(i)` is 48 and their standard deviation is 12 the mean of `w_(i)` 's is 55 and standard deviation of `w_(i) ` is 15 then the value of l and k should be

A

l=2.5, k=5

B

l=-1.25, k=5

C

l=2.5, k=-5

D

l=1.25, k=-5

Text Solution

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The correct Answer is:
D
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