mode

The mode is the value that appears most often in a set of data. For 5, 3, 5, 7 and 5, the number 5 appears three times and is the mode. A set can have no mode — when every value appears the same number of times — or more than one mode, when two or more values tie for most frequent. Unlike the mean and the median, the mode does not have to be a number: the mode of a list of colors is whichever color appears most, which is why the mode is used for categories as well as for quantities. The common error is to answer with the largest value; the mode is about frequency, not size, so a set like 2, 2, 2, 100 has a mode of 2, not 100. The mode is the third measure of center alongside the mean and the median.