3.18 Harmonic Mean

Formula: Reciprocal of Mean of \(\frac{1}{x_i}\)

Reciprocal of \(\frac{\frac{1}{x_1}+\frac{1}{x_2}+...+\frac{1}{x_n}}{n}\)

Thus, \(HM = \frac{n}{\sum \frac{1}{x_i}}\)

Calculate: 2, 4, 8

Answer (click to see)

3.43

For grouped data

• \(HM=\frac{\sum f}{\sum \frac{f}{x}}\)
• For wighted data: \(\frac{\sum w}{\sum \frac{w}{x}}\)