Monday, July 18, 2011

Find Cumulative Frequency In Math

Frequency in math and statistics illustrates how often a phenomenon occurs in a range of values. The results are commonly represented in tabular or graphical forms as frequency distributions, describing how often a data point occurs over a range of values. Cumulative frequency is an important tool in many applications. Geologists, for example, may wish to know how often earthquakes occur in different fault zones within different periods of time --- 100 years, 500 years, 1,000 years. Cumulative frequency is nothing more than the total number of frequencies at or less than a given value.


Instructions


1. Write down the first value in the table of frequency data. For example, say 100 trout weighing 1 lb. or less are caught in a pond in one season. That is the initial cumulative frequency.


2. Add to the figure in Step 1 the next value in the data set. Continuing the example, suppose 55 trout weighing between 1 and 2 lbs. were caught in the same pond, so 100 + 55 = 155 trout. Because you have changed the range of values to include the fish between 1 and 2 lbs., the cumulative frequency of trout caught is 155 trout weighing 2 lbs. or less.


3. Continue to add other data points to obtain further cumulative frequencies. For example, if 12 trout weighing between 2 and 3 lbs. were caught, the cumulative frequency will now be 100 + 55 + 12 = 167 trout weighing 3 lbs. or less were caught.







Tags: trout weighing, cumulative frequency, range values, trout weighing less, weighing less, were caught