Solved: Back-to-Back Relative Frequency Histograms When

Chapter 2, Problem 19

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Back-to-Back Relative Frequency Histograms When using histograms to comparetwo data sets, it is sometimes difficult to make comparisons by looking back and forth betweenthe two histograms. A back-to-back relative frequency histogram has a format that makesthe comparison much easier. Instead of frequencies, we should use relative frequencies (percentagesor proportions) so that the comparisons are not difficult when there are differentsample sizes. Use the relative frequency distributions of the ages of Oscar-winning actressesand actors from Exercise 15 in Section 2-2, and complete the back-to-back relative frequencyhistograms shown below. Then use the result to compare the two data sets.2-4 Graphs That Enlighten and Graphs That DeceiveKey Concept Section 2-3 presented the histogram as a graph that is helpful in learningabout the shape of the distribution of data. The histogram is a graph that enlightens in thesense that it gives us better understanding of data. In this section we introduce other commonlyused graphs that enlighten. We also discuss some graphs that deceive in the sensethat they tend to create impressions about data that are somehow misleading or wrong.The days of charming and primitive hand-drawn graphs are well behind us, andtechnology now provides us with powerful tools for generating a wide variety of differentgraphs. In this section, all figures except Figure 2-19 were generated using technology.89.5Age79.569.559.549.539.529.519.50% 10% 20%Actors50% 40% 30% 30% 40% 50%Actresses20% 10% 0%