AP Statistics Graphs of Quantitative Data and Shape Quiz: 10 Questions with Explanations

A 9B 4C 20D 13

Values of 20 or more are in the last two bars: 9 + 4 = 13. Counting only the bar that starts at 20 gives 9.

A are separated, to show categoriesB touch, because the axis is a number lineC must be different widthsD show only the median

Intervals of a numerical scale run into each other, so bars touch. Gaps are for bar graphs of categorical data.

A Skewed leftB Skewed rightC SymmetricD Bimodal

The tail extends to the left, toward the small values, so the distribution is skewed left. Many students pick right because the tall bars are on the right.

A The medianB A potential outlier separated by a gapC The modeD A cluster

9 is far above the others, separated by a gap of 4 from the next value, so it is a potential outlier.

A Looks like a hillB The graph goes up and downC Skewed right with an outlier at 90, center about 65, and values from 61 to 68 otherwiseD The mean is 65

A complete description mentions shape, outliers, center, and spread in context. The others omit most of the required features.

A uniformB skewed rightC unimodalD bimodal

Two peaks means bimodal. A uniform distribution is flat and a unimodal one has just one peak.

A 14B 6C 40D 20

Add the bar heights: 4 + 9 + 14 + 8 + 3 + 2 = 40. The tallest bar gives only one interval.

A A stemplotB A histogramC A boxplotD A pie chart

A stemplot lists each leaf, so the original data can be recovered. A histogram only shows counts within intervals.

A the bar widths changeB all counts are divided by the same totalC the median changesD the data are removed

Dividing by n rescales the vertical axis only. The pattern of the bars stays the same.

A larger valuesB smaller valuesC centerD median

Skew is named for the direction of the tail. Right-skewed data have a few unusually large values.