均值、中位数和众数的交互式练习活动
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该范例通过一个包含5个类别及其频数的数据表,演示了如何计算均值、中位数和众数。其中某个类别的频数未知,用户可以通过输入框调整该频数,观察三个统计量如何随之变化。核心数学概念是描述性统计中的集中趋势度量,包括均值(算术平均)、中位数(排序后中间值)和众数(出现次数最多的值)。作图要点:使用GeoGebra的Sequence、RemoveUndefined、Insert、Join等命令构建数据列表,通过Textfield和输入框(inputBox1-3)接收用户输入,利用Median、Mean、Mode函数计算统计量,并用TableText和文本对象展示数据表与问题。适合中学数学统计章节的课堂练习或自学,帮助学生直观理解不同频数对集中趋势指标的影响。
GeoGebra 命令及参数
Sequence(Cell[i + 1, 1], i, 1, B3) → ListCategoryValuesSequence(Cell[i + 1, 2], i, 1, B3) → ListFrequencyValuesFromCellsRemoveUndefined(ListFrequencyValuesFromCells) → ListFrequencyValuesRemovedUndefinedInsert(a, ListFrequencyValuesRemovedUndefined, B4) → ListFrequencyValueswithVariableInsert("a", ListFrequencyValuesRemovedUndefined, B4) → ListFrequencyValueswithTextJoin({ListCategoryTitle, ListCategoryValues}) → ListCategoryTextfield(targetmode) → inputBox1Textfield(targetmedian) → inputBox2Textfield(targetmean) → inputBox3Median(Take[ListCategory, 2, 5], Take[ListFrequencyNum, 2, 5]) → medianvalue1Join({ListFrequencyTitle, ListFrequencyValueswithText}) → ListFrequencyVariableTextTableText({ListCategory, ListFrequencyNum}, "c|_") → Table2SolutionTableText({ListCategory, ListFrequencyVariableText}, "c|_") → Table1ProblemJoin({ListFrequencyTitle, ListFrequencyValueswithVariable}) → ListFrequencyVariableSearchTableText({ListCategory, ListFrequencyVariableSearch}, "c|_") → Table3HiddenSearchSum(Take[ListFrequencyVariableSearch, 2]) → totalfrequencyMedian(Take[ListCategory, 2, numberofcategories + 1], Take[ListFrequencyVariableSearch, 2, numberofcategories + 1]) → medianvaluesearchSequence(If[i < numberofcategories, "+", ""], i, 1, numberofcategories) → ListAddSignSequence(Element[ListCategoryValues, i] + "×" + (Element[ListFrequencyValueswithVariable, i] + Element[ListAddSign, i]), i, 1, numberofcategories) → CategoryFrequencyProductListSequence(Element[MatrixAllSortedSearch, 1, i], i, 1, totalfrequency) → ListAllSortedSearchSequence(Polygon[(i - 1, 0), (i, 0), (i, Element[ListAllSortedSearch, i]), (i - 1, Element[ListAllSortedSearch, i])], i, 1, totalfrequency) → DataVisualBarSequence(Text[Element[ListAllSortedSearch, i], (i - 1, Element[ListAllSortedSearch * 1.1, i])], i, 1, totalfrequency) → DataVisualTextMean(Take[ListCategory, 2, numberofcategories + 1], Take[ListFrequencyVariableSearch, 2, numberofcategories + 1]) → meanvaluesearchMode(ListAllSortedSearch) → modesearchVector(((2 * medianposition - 1) / 2, Element[ListAllSortedSearch, totalfrequency]), ((2 * medianposition - 1) / 2, Max[Element[ListAllSortedSearch, totalfrequency] * 0.5, Element[ListAllSortedSearch, medianposition] * 1.2])) → medianpositionpointerSum(CategoryFrequencyProductList) → TextSumCategoryFrequency