Final answer:
The fourth method to summarize numerical data is measures of central tendency, which includes the mean, median, and mode.
Step-by-step explanation:
The fourth method to summarize numerical data is called measures of central tendency. Measures of central tendency are single values that represent the center or typical value of a data set. The three commonly used measures of central tendency are the mean, median, and mode. The mean is calculated by adding up all the values in the data set and dividing by the number of values. The median is the middle value when the data set is ordered from smallest to largest. The mode is the value that appears most frequently in the data set.