Stem-and-leaf plots

Learning Objectives Construct an ordered stem-and-leaf plot for a given quantitative data set. Interpret a stem-and-leaf plot to identify the shape, spread, clusters, and potential outliers of a data distribution. Calculate the mean, median, mode, and range for a data set represented by a stem-and-leaf plot. Construct and interpret a back-to-back stem-and-leaf plot to compare the distributions of two data sets. Determine the five-number summary (minimum, Q1, median, Q3, maximum) from an ordered stem-and-leaf plot. Connect the visual 'shape' of a stem-and-leaf plot to the concept of a data distribution, linking it to the study of figures. How can we quickly see the 'shape' of a class's test scores to see if most students did well or poorly? 📊 This t...

TermDefinitionExample StemThe leading digit or digits of a data value. It forms the main 'stem' of the plot.In the number 84, the stem is 8. LeafThe last digit of a data value. It branches off from the stem.In the number 84, the leaf is 4. Key (or Legend)An essential part of the plot that explains how to interpret the stem and leaf values.Key: 8 | 4 means 84 Data DistributionThe way in which data is spread out or clustered. A stem-and-leaf plot provides a visual representation, or 'figure', of this distribution.A plot might show a distribution that is symmetric (like a bell curve) or skewed to one side. Back-to-back Stem-and-leaf PlotA plot that uses a central stem to compare two different data sets. The leaves for one set are on the left, and the leaves for the other...

Median Position Position = \frac{n+1}{2} Use this formula to find the position of the median in an ordered data set, where 'n' is the total number of data values. Count from the smallest value to find the median. Range Range = Maximum Value - Minimum Value The range measures the total spread of the data. It is calculated by subtracting the smallest value (minimum) from the largest value (maximum) in the data set. Interquartile Range (IQR) IQR = Q_3 - Q_1 The IQR measures the spread of the middle 50% of the data. It is calculated by subtracting the first quartile (Q1, the median of the lower half) from the third quartile (Q3, the median of the upper half).