Graphs and displays
Every plot the exam expects you to read, build, and compare, defined in one place.
20 terms
Back-to-back stemplotA back-to-back stemplot compares two groups on one shared column of stems, with one group's leaves read leftward and the other group's rightward.Bar graphA bar graph displays a categorical variable using separated bars whose heights show the count or relative frequency of each category.Bin widthBin width is the size of each equal-width interval in a histogram, and it controls how much detail or smoothing the display shows.BoxplotA boxplot pictures the five-number summary as a box from the first quartile to the third, a line at the median, and a whisker toward each extreme.Comparative dotplotA comparative dotplot draws one dotplot per group on a shared horizontal scale, so centers, spreads, and shapes can be compared value by value.Density curveA density curve is a smooth curve that models a distribution, never dipping below the axis, with total area underneath exactly equal to 1.DotplotA dotplot displays quantitative data by stacking one dot above a number line for each observation at its value.Frequency polygonA frequency polygon is a line graph of a frequency distribution, made by connecting points plotted above each histogram bin's midpoint at the bin's height.Frequency tableA frequency table lists the categories or value ranges of a variable alongside the count of observations in each.HistogramA histogram displays quantitative data by grouping values into equal-width intervals and drawing a bar for the count in each interval.Mosaic plotA mosaic plot shows two categorical variables as tiles, with bar widths scaled by group size and segment heights giving conditional proportions.Normal probability plotA normal probability plot graphs ordered data against the z-scores a normal model predicts; a roughly straight line means roughly normal.Ogive (cumulative relative frequency graph)An ogive is a cumulative relative frequency graph: each point gives the proportion of values at or below a number, so the curve rises to 1.Pie chartA pie chart displays a categorical variable as slices of a circle, with each slice's area equal to that category's share of the whole.ScatterplotA scatterplot graphs paired values of two quantitative variables as points, showing the direction, form, and strength of their relationship.Segmented bar chartA segmented bar chart stacks one bar per group, splitting each bar to show how that group divides across a second categorical variable.Side-by-side boxplotA side-by-side boxplot draws one boxplot per group on a shared scale, so you can compare center, spread, and skew across groups at a glance.StemplotA stemplot, or stem-and-leaf plot, displays quantitative data by splitting each value into a leading stem and a trailing leaf digit.Time plotA time plot graphs a quantitative variable against time on the horizontal axis, with the points usually connected in time order.Two-way tableA two-way table displays counts for two categorical variables at once, with one variable's categories as rows and the other's as columns.