South Dakota School of Mines & Technology Data Analysis Industrial Engineering

Data Analysis Box Plots Industrial Engineering

Box Plots Problem with empirical is we may simply not have enough data For small data sets, analysts often like to provide a rough graphical measure of how data is dispersed Consider our student data 2.4, 2.7, 2.8, 2.9, 3.0, 3.0, 3.1, 3.3, 3.5, 3.9

Box Plots Ranked student Gpa data 2.4, 2.7, 2.8, 2.9, 3.0, 3.0, 3.1, 3.3, 3.5, 3.9 Min = 2.4 Max = 3.9 2.4 3.9

Box Plots Ranked student Gpa data 2.4, 2.7, 2.8, 2.9, 3.0, 3.0, 3.1, 3.3, 3.5, 3.9 Median = (3.0+3.0)/2 = 3.0 2.4 3.9 3.0

Box Plots Ranked student Gpa data 2.4, 2.7, 2.8, 2.9, 3.0, 3.0, 3.1, 3.3, 3.5, 3.9 Median Bottom= (2.7+2.8)/2 = 2.75 2.4 3.9 3.0 2.75

Box Plots Ranked student Gpa data 2.4, 2.7, 2.8, 2.9, 3.0, 3.0, 3.1, 3.3, 3.5, 3.9 Median Top = (3.3+3.5)/2 = 3.4 2.4 3.9 3.0 2.75 3.4

Box Plots Ranked student Gpa data 2.4, 2.7, 2.8, 2.9, 3.0, 3.0, 3.1, 3.3, 3.5, 3.9 2.4 3.9 3.0 2.75 3.4

Fail Time Data Lower Quartile = 6.1 Min = 0.5 Median = 14.3 Max = 73.8 Upper Quartile = 26.7 Min = 0.5 Max = 73.8 0.5 6.1 14.3 26.7 73.8

Class Problem The following data represents sorted observations on deviations from desired diameters of ball bearings. Compute a box plot.