Data Distribution – Stem & Leaf Plot

Data Distribution – Stem & Leaf Plot The purpose of a stem and leaf plot is to indicate how a data set is distributed. data distribution – data distribution refers to how the data values in a set are spread (i.e. range between high and low values, clusters, where there might be no data, spread evenly or randomly etc.) stem and leaf plot – an organization/display of data to show the distribution of the data based on place value

Data Distribution – Stem & Leaf Plot Create a stem and leaf for the following data which represents the # of people to have x-rays over a 16 day period 25 31 20 32 13 14 43 02 57 23 36 32 33 32 44 71

Data Distribution – Stem & Leaf Plot Step 1 – although not completely necessary it may help to arrange the data in order 02 13 14 20 23 25 31 32 32 32 33 36 43 44 57 71

Data Distribution – Stem & Leaf Plot Step 2 – Establish 2 columns, one for the stems and one for the leaves. Enter each # in the set by recording the last digit as the leaf and the remaining/leading digit(s) as the stem. (Once a stem has been established it can be used for all the numbers that require that stem. For example once a # such as 25 has been entered and the stem of 2 established it could be used for other #’s in the twenties that require a stem of 2 and only the leaves would be entered.)

Stem (leading digit(s)) Leaf (last digit) 0 2 1 3 4 2 0 3 5 3 1 2 2 2 3 6 4 3 4 5 7 6 7 1 Each data value is read by combining the stem and a leaf. For example in the second row there are 2 values – 13 and 14 The shape of the plot indicates the distribution of the data so neatness (i.e. spacing) is important. Conclusions – Comment on the distribution of the data.

They commonly x-ray 30-40 patients per day It is not common to x-ray less than 10 patients per day or more than 50 They have never x-rayed 60-70 patients in a day