The sum of the absolute frequencies is equal to the total number of data, represented bas $$N$$. 1  Relative frequency: the result of dividing the absolute frequency of a certain value by the total number of data.  The sum of the relative frequencies is equal to $$1$$. We can prove this easily by factorizing $$N$$.
Periodical cicadas emerge from underground every 13 or 17 years, depending upon which brood the cicadas belong to. The year a particular brood emerges often differs from other broods and is also dependent on geography. The periodical cicada, although unrelated, is often mistakenly called a locust.
17 years in the making, this spring's cicada invasion generates early buzz. By Cosmic Log. Email. When the ground warms to 64 degrees Fahrenheit, a group of cicadas known as Brood II will infect the East Coast from North Carolina to New York's Hudson Valley.NBC's Anne Thompson reports.7 years in the making, this spring's cicada invasion generates early buzz. By Cosmic Log. Email. When the ground warms to 64 degrees Fahrenheit, a group of cicadas known as Brood II will infect the East Coast from North Carolina to New York's Hudson Valley. NBC's Anne Thompson reports.