Harmonic mean of $$$11$$$, $$$15$$$

Find the harmonic mean of $$$11$$$, $$$15$$$.

The harmonic mean of data is given by the formula $$$H = \frac{n}{\sum_{i=1}^{n} \frac{1}{x_{i}}}$$$, where $$$n$$$ is the number of values and $$$x_i, i=\overline{1..n}$$$ are the values themselves.

Since we have $$$2$$$ points, $$$n = 2$$$.

The sum of the reciprocals of the values is $$$\frac{1}{11} + \frac{1}{15} = \frac{26}{165}$$$.

Therefore, the harmonic mean is $$$H = \frac{2}{\frac{26}{165}} = \frac{165}{13}$$$.

The harmonic mean is $$$\frac{165}{13}\approx 12.692307692307692$$$A.