When can there be no mode?
A mode is the number that appears most frequently in data. For
instance, in the set 2,3,3,5,7,7,7,7,8,9,9 the mode is 7. Something
is bimodal if two numbers have the equally high frequency. Data is
trimodal if there are three equally frequent numbers, and so on. If
all numbers occur at equal frequency, for instance in the set
2,2,4,4,5,5,7,7,8,8,9,9, then there is no mode.