Box Plots Flashcards

All 6 cards in this deck

What five values does a box plot show?

The least value, lower quartile, median, upper quartile and greatest value.

On a box plot, which distances give the range and which give the interquartile range?

Range = distance between the whisker ends (greatest $-$ least); IQR = width of the box (upper quartile $-$ lower quartile).

True or false? The line drawn inside the box of a box plot shows the mean.

False. It shows the median.

What are the steps to draw a box plot from a five-figure summary?
e.g. least $8$, LQ $25$, median $34$, UQ $42$, greatest $74$

1. Draw the box from the LQ to the UQ: $25$ to $42$
2. Draw a line inside the box at the median: $34$
3. Draw whiskers out to the least and greatest values: $8$ and $74$

When drawing a box plot using values read from a cumulative frequency graph, where do the whisker ends come from?

From the least and greatest values given in the question — the cumulative frequency graph does not show them.

When comparing two distributions shown by box plots, what two things must you compare?

A measure of average (the medians) and a measure of spread (the IQR or the range), with at least one comparison in the context of the question.