21. This distance can also be expressed in terms of the arithmetic mean of gene identity. 22. The EDI value for a given country is thus the arithmetic mean of the four indicators. 23. The most common measures of central tendency are the arithmetic mean , the median and the mode. 24. Life expectancy is by definition an arithmetic mean . 25. If a summit elevation or prominence has a range of values, the arithmetic mean is cited. 26. In fact, it sometimes produces an extreme difference between the weighted average and the arithmetic mean . 27. In the infinite case, the weighted arithmetic mean has to be replaced by an appropriate integral. 28. Then compute the arithmetic mean of these points. 29. MTBF can be calculated as the arithmetic mean ( average ) time between failures of a system. 30. If all the weights are equal, then the weighted mean is the same as the arithmetic mean .