Let\[{{x}_{1}},{{x}_{2}},.....,{{x}_{n}}\]be n observations such that \[\Sigma x_{i}^{2}=400\]and\[\Sigma {{x}_{i}}=80\]. Then, a possible value of n among the following is
AIEEE Solved Paper-2005
A)12
B) 9
C) 18
D) 15
Correct Answer:
C
Solution :
Using the inequality, AM of m th power > m th power of AM, if Then