Lesson 2: Draw Inferences from Data

Property

A dot plot displays numerical data by placing dots above a number line at each data value's location.
When interpreting dot plots, we analyze their shape by identifying key features: clusters (groups of data points close together), gaps (intervals with no data), peaks (values with the highest frequency), and outliers (values significantly separated from the main data).
These shape characteristics help us understand the distribution and patterns within the dataset.

Examples

Property

When comparing populations, we use measures of center to summarize and contrast different groups. The mean and median each provide a single-number summary of a population's data. The choice between mean and median depends on the distribution shape:

Skewed Left: Extreme values pull the mean to the left of the median. Median is a better measure of center for comparison.

Property

Box plots allow us to visually compare two or more populations by displaying their five-number summaries side by side. When comparing populations, we can analyze differences in center (median position), spread (box width and whisker length), and overall distribution shape to draw conclusions about how the populations differ.

Examples