Harmonic mean of $$$7$$$, $$$20$$$

Find the harmonic mean of $$$7$$$, $$$20$$$.

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 $$$\frac{1}{7} + \frac{1}{20} = \frac{27}{140}$$$.

Therefore, the harmonic mean is $$$H = \frac{2}{\frac{27}{140}} = \frac{280}{27}$$$.

The harmonic mean is $$$\frac{280}{27}\approx 10.37037037037037$$$A.