Page 201 - BA2 Integrated Workbook STUDENT 2018
P. 201

Risk 1: Summarising and analysing data




               3.3   Histograms

               When we looked at bar charts we saw that the vertical height of the bar represented
               the frequency while the horizontal (x) axis simply showed the labels of the items or
               classes. With histograms the frequency is represented by the area of a block or
               rectangle.

               More specifically, a histogram is a diagram consisting of rectangles whose area is
               proportional to the frequency of a variable and whose width is equal to the class
               interval. The x-axis is the variable being measured and the y-axis is the
               corresponding frequency.



                        Frequency
                                   500

                                   400


                                   300

                                   200

                                   100
                                    0
                                          10  20  30      40  50     60
                                                             Time (minutes)



                  Illustrations and further practice


                  Go through illustration 7

























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