A frequency table describes data. The first column gives the number of distinct values or categories of a variable. The second column of a frequency table lists the number of observations in a category. The third column gives the percentage, which is the frequency, divided by the number of observations in all categories. Studying frequency tables is often useful in the initial stages of data analysis.
An example of a frequency table is given below. This table gives the number of returning visitors to this site (stattucino) on march 26 2003. This variable is a binomial variable, because it has two categories: first visit, and two or more visits. From the table we learn that 89.15 percent of the visits was a first time visit, whereas 10.85 percent has visited this site before, and returned to this site. If we call first visit the probability of succes, then the parameter p in the binomial distribution would be .8915.
Frequencies Returning Visitors
| Value | Frequency | Percentage |
| first visit | 156.0 | 89.15 |
| two or more visits | 19.0 | 10.85 |