The mean of n observations is x . If three observations n +1, n -1,2 n -1 are added such that mean remains same, then value of n is

Step-by-step solution

Let the n observations be x₁, x₂, , x_ n According to have given condition; we get aligned & x₁+x₂+ +x_n n & = x₁+x₂+ +x_n+ n +1+ n -1+2 n -1 n +3 & x = x₁+x₂+ +x_n+4 n -1 n +3 & x = ( x₁+x₂+ +x_n n )+4 n -1 n +3 aligned array ll & x = n x +4 n -1 n +3 & n x +3 x = n x +4 n -1 & 3 x =4 n -1 & n = 3 x +1 4 array