If the arithmetic, geometric and harmonic means between two positive real numbers be $A,\;G$ and $H$, then
${A^2} = GH$
${H^2} = AG$
$G = AH$
${G^2} = AH$
${2^{\sin \theta }} + {2^{\cos \theta }}$ is greater than
Given a sequence of $4$ numbers, first three of which are in $G.P.$ and the last three are in $A.P$. with common difference six. If first and last terms in this sequence are equal, then the last term is
If ${A_1},\;{A_2};{G_1},\;{G_2}$ and ${H_1},\;{H_2}$ be $AM's,\;GM's$ and $HM's$ between two quantities, then the value of $\frac{{{G_1}{G_2}}}{{{H_1}{H_2}}}$ is
The reciprocal of the mean of the reciprocals of $n$ observations is their
If first three terms of sequence $\frac{1}{{16}},a,b,\frac{1}{6}$ are in geometric series and last three terms are in harmonic series, then the value of $a$ and $b$ will be