2.5c Measures of Central Tendency
Sociologists use measures of central tendency to describe the average or typical. There are three ways to calculate an average or measure of central tendency: the mean, the median, or the mode.
Mean
The mean is the arithmetic average of a set of numbers, which is calculated by adding all the numbers and dividing by the number of cases. Using the data in Figure 2.12, the mean divorce rate for women in the United States is 7. The formula for calculating the mean is in Table 2.5.
Figure 2.12
U.S. Divorce Rate Per 1,000 Women 15 Years and Over, 2023
Note: Data is rounded to whole numbers to simplify the math for illustrative purposes. Based on data From the U.S. Census Bureau. (2023a). Divorce rate per 1,000 women 15 years and over (divorces in the last year per 1,000 women)/Table R1253. https://www.census.gov/acs/www/data/data-tables-and-tools/ranking-tables/. In the public domain. Geographic divisions based on Centers for Disease Control and Prevention. (2025). Geographic division or region. https://www.cdc.gov/nchs/hus/sources-definitions/geographic-region.htm. In the public domain. Created with mapchart.net
Table 2.5
The Formula for Calculating a Mean
| Formula for Calculating a Mean | Example Using the Figure 2.12 |
| Sum of all numbers ÷ total number of values = mean | (6 + 6 + 6 + 7 + 8 + 8 + 8 + 9 + 9) ÷ 9 = 7 |
By author.
Median
The median is the value or number occurring in the middle of a dataset. It is important to calculate because extreme values (or outliers) can lead to misleading conclusions (or skew the data). For example, the median income is a better measure of average income because many more households earn lower incomes and a few households earn more extreme incomes (over a million dollars). The mean would not accurately reflect household income for the typical household. In the case of divorce rates, the mean (7) and median (8) are close (see Table 2.6). Therefore, there are not any regions with exceptionally high or low divorce rates leading to misleading conclusions about divorce in the United States.
Table 2.6
Divorce Rate Per 1,000 Women 15 Years and Over by U.S. Region, 2023
| Region | Divorce Rate |
| New England | 6 |
| Middle Atlantic | 6 |
| East North Central | 6 |
| West North Central | 7 |
| Pacific | 8 |
| Mountain | 8 |
| West South Central | 8 |
| East South Central | 9 |
| South Atlantic | 9 |
Based on data From the U.S. Census Bureau. (2023a). Divorce rate per 1,000 women 15 years and over (divorces in the last year per 1,000 women)/Table R1253. https://www.census.gov/acs/www/data/data-tables-and-tools/ranking-tables/. In the public domain. Geographic divisions based on Centers for Disease Control and Prevention. (2025a). Geographic division or region. https://www.cdc.gov/nchs/hus/sources-definitions/geographic-region.htm. In the public domain.
Mode
The mode is the value or number that appears most often in the dataset. It is the only measure of central tendency that can be determined for non-numerical variables such as gender or race. The frequency of a value is another way of understanding the patterns in the data. The divorce rate data has two values that occur most often, making it bimodal (or having two modes). The modes are 6 and 8.
Table 2.7 summarizes each measure of central tendency for divorce rates in the United States. In this data, each measure is close, suggesting no extreme outliers among the regions of the United States. Overall, divorce rates vary some across the United States, suggesting that divorce rates and the region of the country are correlated. Thus, something about the culture, the law, or both makes divorce more or less likely in some regions.
Table 2.7
The Measures of Central Tendency for the U.S. Divorce Rate, 2023
| Measure of Central Tendency | Value |
| Mean | 7 |
| Median | 8 |
| Mode | 6 and 8 |
Note: The mean divorce rate is 7 per 1,000 women 25 years and over. The median divorce rate is 8 per 1,000 women 15 years and over. The modal divorce rate is 6 and 8 per 1,000 women 15 years and over. Based on Data From the U.S. Census Bureau. (2023a). Divorce rate per 1,000 women 15 years and over (divorces in the last year per 1,000 women)/Table R1253. https://www.census.gov/acs/www/data/data-tables-and-tools/ranking-tables/. In the public domain.