Thank you for reporting, we will resolve it shortly
Q.
The reciprocal of the mean of the reciprocals of $n$ observation is the :
Statistics
Solution:
Let $x_{1}, x_{2}, \ldots \ldots \ldots . . x_{n}$ be $n$ observation.
Now, reciprocals of $n$ observations are
$\frac{1}{ x _{1}}, \frac{1}{ x _{2}}, \ldots \ldots, \frac{1}{ x _{ n }}$
Now, mean of the reciprocals of $n$ observation.
$=\frac{1}{ x _{1}}+\frac{1}{ x _{2}}+\ldots \ldots+\frac{1}{ x _{ n }}$
Now, reciprocal of mean of the reciprocals of $n$ observations
$=\frac{ n }{\frac{1}{ x _{1}}+\frac{1}{ x _{2}}+\ldots \ldots .+\frac{1}{ x _{ n }}}=$ Harmonic mean