As mean is a linear operation, so if each observation is multiplied by λ and decreased by 25 then the mean becomes 75 λ−25. According to the question, 75λ−25=75⇒λ=34
The mean of a set of 30 observations is 75 . If each other observation is multiplied by a nonzero number λ and then each of them is decreased by 25 , their mean remains the same. The λ is equal to equal to {0}
Held on 15 Apr 2018 · Verified 6 Jul 2026.
310
34
31
32
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