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AP EAMCET · Maths · Statistics

The mean and variance of n observations x1, x2, x3,, xn are 5 and 0 respectively. If i=1nxi2=400, then the value of n is equal to

  1. A 80
  2. B 25
  3. C 20
  4. D 16
Verified Solution

Answer & Solution

Correct Answer

(D) 16

Step-by-step Solution

Detailed explanation

The variance of n observation is σ2=1n∑i=1nxi2-x¯2, where x¯ is the mean of the observations. Hence, putting the given values, we get 0=1n400-52 ⇒400n=25 ⇒n=16.