Box and Whisker Plots

Box and Whisker Diagrams Or Upper quartile Or Lower quartile Box and Whisker Diagrams These consist of a thin rectangle (box) and two lines (whiskers). The full length of the diagram shows the range of the data, which is the difference between the top value and bottom value

S U C S ANALYSIS - Comparing data sets: writing I notice …….. Make comment on The variation in the data: The shape of the data Unusual points The “centre” of the distribution, roughly where the “average” is located How spread out it is S U C S

What do you notice about the SUMMARY STATISTICS? Compare and quote the average (the measures of centre), the median. I notice that the median height for boys is higher for boys than for girls. The median for boys is 180cm compared to 165cm for girls, a difference of 15cm. Compare and quote the Upper quartile and the Lower quartile I notice that the lower quartile for boys is 172cm compared to 160cm for girls. I notice that the upper quartile for boys is 190cm compared to 170cm for girls.

What do you notice about the AVERAGE and SPREAD of the data What do you notice about the SHAPE of the data? What do you notice about the AMOUNT OF DIFFERENCE between the data sets? What do I notice about the proportions?

If there is no overlap of the boxes, or only a very small overlap, make the claim “B tends to be bigger than A back in the populations. If the median for one of the samples lies outside the box for the other sample (“more than half of the B group are above three quarters of the A group”) make the claim “B tends to be bigger than A” back in the populations. BUT only for samples between 20 and 40 in such group) “Cannot tell” unless both samples are huge “Cannot tell” OBSERVED DATA FROM SAMPLE