Final answer:
A box plot is the chart type that displays both the center and spread of data, with its median indicating the center and the interquartile range representing the spread.
Step-by-step explanation:
The chart type that shows both the center and spread of a data set is the box plot. A box plot, also known as a box-and-whisker plot, visually displays the distribution of a data set by indicating its middle 50 percent or the interquartile range (IQR), which lies between the first quartile (Q1) and the third quartile (Q3). It also provides information about the median, which represents the center of the data. Additional details such as the minimum and maximum values and potential outliers are depicted with the 'whiskers' and points beyond the whiskers, respectively. In contrast, bar charts are used to represent frequencies of different categories, bubble plots show data with a third dimension often representing size, and pie charts are used to compare parts of a whole. Box plots are particularly useful when comparing the spread and median of different data sets.