Harmonic Mean
- Harmonic Mean = $$\dfrac{n}{\frac{1}{x_{1}}+\frac{1}{x_{2}}+\frac{1}{x_{3}}+...+\frac{1}{x_{n}}}$$
- If a, b, c, d...are the given numbers in H.P then the Harmonic mean of 'n' terms=$$\frac{Number of terms}{\frac{1}{a}+\frac{1}{b}+\frac{1}{c}+....}$$
- If two numbers a and b are in H.P then the Harmonic mean= $$\frac{2ab}{a+b}$$
