frequency tables in statistics
Frequency tables are a way of groping various outcomes in a sample or population in statistics. That is when running threw a population, or a sample of a population of data there are going to be instances in that sample that meet a cretin criteria, and thus can be grouped in that criteria. Say for example you have a collection of grades for each student in a class, there is groping them by a letter grade, or by a number range. In any case the result is a table where all the students fall into each group, and there is a count for each group, such a table can oftetn be called a frequency table.
1  Basic frequency tables example with javaScript
For basic example of a frequency table there is some javaScript that has to do with a simple grades in a class example. For the sake of keeping this basic the population is just an array of letter grades, rather than objects with more detailed information for each test. To create a frequency table for this array of letter grades I just need to run threw the population and create a count for each letter grade.


The frequency table can the be used to figure all kinds of useful values about the outcome of this hypothetical test. For example I can run over the frequency table and create a new value for each group that is the count over the total number of students to get percentage value for each group.