The mean and the variance of five observation are 4 and 5.20, respectively. If three of the observations are 3, 4 and 4; then then absolute value of the difference of the other two observations, is :

Question

The mean and the variance of five observation are 4 and 5.20, respectively. If three of the observations are 3, 4 and 4; then then absolute value of the difference of the other two observations, is : (A) 1 (B) 3 (C) 7 (D) 5

Tardigrade Admin · Accepted Answer

mean barx = 4 , σ2 =5.2 , n=5,. x1 = 3, x2 = 4 = x3 ∑ xi = 20 x4 + x5 = 9 .....(i) (∑ xi2/x) - ( barx)2 σ2 ⇒ ∑ xi2 = 106 x42 + x52 = 65......(ii) Using (i) and (ii) (x4 - x5)2 = 49 | x4 - x5| = 7

Q. The mean and the variance of five observation are 4 and 5.20, respectively. If three of the observations are 3,4 and 4; then then absolute value of the difference of the other two observations, is :

1

3

7

5

meanxˉ=4,σ2=5.2,n=5,.x1​=3,x2​=4=x3​ ∑xi​=20 x4​+x5​=9.....(i) x∑xi2​​−(xˉ)2σ2⇒∑xi2​=106 x42​+x52​=65......(ii) Using (i) and (ii) (x4​−x5​)2=49 ∣x4​−x5​∣=7

Q. The mean and the variance of five observation are 4 and $5.20$ , respectively. If three of the observations are $3, 4$ and 4; then then absolute value of the difference of the other two observations, is :