Displaying Quantitative Data with Graphs

Dotplot

Dotplot

shows each data value as a dot above its location on a number line

Symmetric

a distribution is roughly symmetric if the right side of the graph (containing half of the observations with the largest values) is approximately a mirror image of the left side

Skewed to the right

a distribution is skewed to the right if the right side of the graph id much longer than the left side

Skewed to the left

a distribution is skewed to the left if the left side of the graph is much longer than the right side

Stemplot

shows each data value separated into two parts: a stem, which consists of all but the final digits, and a left, the final digit. The stems are ordered form lowest to highest and arranged in a vertical column. The leaves are arranged in increasing order out from the appropriate stems

Histogram

shows each interval of values as a bar. The heights of the bars show the frequencies or relative frequencies of values in each interval