Harmonic mean is a type of average used to calculate the central tendency of a set of numbers. It is calculated by taking the reciprocal of each number in the set, adding them together, and then taking the reciprocal of the sum.

One example of using harmonic mean is in calculating the average speed of a vehicle over a certain distance. In this case, the harmonic mean would be calculated by taking the reciprocal of each speed measurement, adding them together, and then taking the reciprocal of the sum. This would give a more accurate representation of the average speed, as it takes into account the slower speeds as well as the faster speeds.

Another example of using harmonic mean is in calculating the average grade in a class. In this case, the harmonic mean would be calculated by taking the reciprocal of each student’s grade, adding them together, and then taking the reciprocal of the sum. This would give a more accurate representation of the average grade, as it takes into account the lower grades as well as the higher grades.

Overall, harmonic mean is useful in situations where it is important to consider the extremes of a set of numbers, rather than just the average or the median. It can provide a more accurate representation of the central tendency in a set of numbers, and is particularly useful in situations where there are a few extremely high or low values.