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  • Stem-and-Leaf 草地

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    A zoologist takes the weights of male and female chimpanzees at 1 year of age. She finds the following data , in pounds, and places it in order from smallest to largest.
    ::动物学家在1岁时将男性和女性黑猩猩的重量计算为1岁。她发现了以下按磅计的数据,并将数据排列成从最小到最大的。

    Females: 14, 17, 19, 19, 20, 21, 23, 24
    ::女性:14、17、19、19、20、21、23、24

    Males: 18, 22, 24, 25, 26, 28, 31, 32, 34
    ::男性:18、22、24、25、26、28、31、32、34

    How can the zoologist represent this data in order to compare the males and the females in the same data display?
    ::动物学家如何能代表这些数据来比较同一数据显示中的男性和女性?

    In this concept, you will learn to use stem-and-leaf plots.
    ::在这一概念中,你将学会使用干叶地块。

    Stem and Leaf Plot
    ::Stem 和 Leaf 草地

    Measures of central tendency are an important method for interpreting a set of data. For a visual representation of data, plots or graphs can be used. Each type of visual tool has advantages and the best type of plot or graph depends on the situation. Indeed, sometimes it is a matter of preference as many different graphs could be used to illustrate the same data.
    ::中央趋势的测量是解释一组数据的一个重要方法。 对于数据、图纸或图表的直观表达,可以使用。每一种视觉工具都有优势,最佳类型的图纸或图表取决于情况。事实上,有时这是一个偏好问题,因为许多不同的图表可以用来说明相同的数据。

    One common type of data visualization is a stem-and-leaf plot . Consider a stem and its leaves. The stem is a strong base from which the leaves sprout. This is the idea of a stem-and-leaf plot. They visually present groups of data and tendencies quickly while at the same time showing every single piece of data.
    ::一种常见的数据可视化类型是干叶图案。 考虑一个干叶图案。 考虑一个干叶图案及其叶子。 干叶是叶芽的坚实基础。 这是干叶图案的理念。 他们以视觉方式快速呈现一组数据和趋势, 同时显示每一份数据 。

    Stem-and-leaf plots are organized according to the largest base ten value and the smaller base ten values.
    ::Stem-and-leaf地块按最大的10基值和较小的10基值排列。

    Let’s look at an example.
    ::让我们举个例子。

    An accountant must consider the cost of healthcare for the employees at a company. The healthcare costs are based on age of the employees. She finds that the ages of the employees are as follows: 32, 19, 37, 22, 25, 46, 58, 35, 41, 45, 35, 27, 29, 42, 53, 70, 56, 34, 29, 30, 21, 24, 27, and 45.
    ::会计必须考虑公司雇员的保健费用,保健费用根据雇员的年龄计算,她认为雇员的年龄如下:32、19、37、22、25、46、58、35、41、45、35、27、29、42、53、70、56、34、29、30、31、24、27和45。

    This data is difficult to understand in an unorganized list. Measures of central tendency could be calculated but they would not help to determine healthcare costs. A stem-and-leaf plot will give her a better idea of numbers of employees per age group.
    ::这些数据很难在无组织清单中理解。 可以计算中心趋势的度量,但无助于确定医疗成本。 干叶图能让她更好地了解每个年龄组的雇员人数。

    To create a stem-and-leaf plot, the data must first be put in order from smallest to largest:
    ::为了创建干叶图,必须首先将数据从最小变为最大:

    19, 21, 22, 24, 25, 27, 27, 29, 29, 30, 32, 34, 35, 35, 37, 41, 42, 45, 45, 46, 53, 56, 58, 70.

    Now, stem values must be chosen. That means to choose values that would be the first digit(s) of appropriate groupings. In this case, because our youngest employee is 19 and the oldest is 70, the tens place can be used as the stem.
    ::现在,必须选择干值。 这意味着选择适当组别的第一个数字值。 在此情况下,由于我们最小的雇员是19岁,最年长的雇员是70岁, 数十个地方可以用作干茎。

    Construct the stem vertically, as shown below. Then, place each piece of data, the leaves, in the plot, next to its stem. The leaves must be placed in order, only separated by a column. The stem, the tens place, is not repeated.
    ::垂直构造树干, 如以下所示 。 然后, 将每块数据, 叶子, 在树干旁边, 叶子必须按顺序排列, 只用柱子分隔 。 树干, 即 10 个, 不再重复 。

    Stem Leaves 1 9 2 1 , 2 , 4 , 5 , 7 , 7 , 9 , 9 3 0 , 2 , 4 , 5 , 5 , 7 4 1 , 2 , 5 , 5 , 6 5 3 , 6 , 8 6 7 0

    ::StemLeaves 1921,2,4,4,5,7,7,9,9,930,2,4,4,5,5,741,2,5,5,5,653,6,8670

    The stem-and-leaf plot is complete.
    ::干叶地已经完工了

    Now, look at the plot. What trends are visible?
    ::现在,看看图案。什么趋势是可见的?

    The bulk of the employees are in their 20’s and 30’s. By counting, the can be quickly located. The importance of lining up the numbers in columns is also visible. The number of data items in each row is readily available.
    ::大部分雇员在20到30岁之间。通过计算,可以很快找到位置。将数字排在列内的重要性也显而易见。每行的数据项目数量随处可见。

    If the situation had used numbers in the hundreds, then the hundreds would have become the largest stem. If it had been in the thousands, then the thousands would have been the largest stem.
    ::如果用上百个数字,那么上百个就会成为最大的干线。 如果用上千个,那么上千个就会成为最大的干线。 如果用上千个,那么上千个就会成为最大的干线。

    If you have two data sets with similar values, you can plot them all on one stem-and-leaf plot by drawing leaves on either side of the stem - this is called a double stem-and-leaf plot.
    ::如果您有两套具有类似值的数据集, 您可以通过在树干两侧绘制叶叶树叶图 — 这叫做双干叶草图。

    Examples
    ::实例

    Example 1
    ::例1

    Earlier, you were given a problem about  the scientists who collected weights of chimpanzees and got the following data.
    ::早些时候,你得到一个问题 关于科学家收集黑猩猩重量 并获得以下数据。

    Females: 14, 17, 19, 19, 20, 21, 23, 24
    ::女性:14、17、19、19、20、21、23、24

    Males: 18, 22, 24, 25, 26, 28, 31, 32, 34
    ::男性:18、22、24、25、26、28、31、32、34

    You need to draw a double stem-and-leaf plot. The female data on the left begins with smallest data closest to the stem and increases as you go left.
    ::您需要绘制双干叶图。 左边的女性数据以最接近干叶的最小数据开始, 在左侧增加数据 。

    Females Stem Males 9 , 9 , 7 , 4 1 8 4 , 3 , 1 , 0 2 2 , 4 , 5 , 6 , 8 3 1 , 2 , 4

    ::斯泰姆马莱斯9,9,7,418,3,1,022,4,5,6,831,4

    Some inferences to be made from this double stem-and-leaf plot:
    ::从这个双干叶地块中可以得出一些推论:

    You can see from the stem-and-leaf plot that the tendency is for the males to weigh more than the females after a year.
    ::你可以从干叶图中看到,趋势是雄性在一年后比雌性重。

    You can also see that there are more males in this group than females.
    ::您也可以看到,这一组中的男性多于女性。

    Example 2
    ::例2

    Create a stem-and-leaf plot of the mass of geodes found at a volcanic site. Scientists measured 24 geodes in kilograms and got the following data:
    ::绘制火山地点发现的大地测量质量的干叶图。 科学家测量了24个以公斤计的大地测量结果,并获得以下数据:

    0.8, 0.9, 1.1, 1.1, 1.2, 1.5, 1.5, 1.6, 1.7, 1.7, 1.7, 1.9, 2.0, 2.3, 4.1, 4.8, 5.3, 5.5, 5,7, 6.8, 7.0, 7.1, 7.5, 9.6

    Build a stem-and-leaf plot to organize the data.
    ::构建一个干叶图以组织数据 。

    Stem Leaves 0 8 , 9 1 1 , 1 , 2 , 5 , 5 , 6 , 7 , 7 , 9 2 0 , 3 3 4 1 , 8 5 3 , 7 6 8 7 0 , 1 , 5 8 9 6

    ::StemLeaves08,911,1,2,5,5,5,6,7,7,7,920,3341,853,76870,1,5896

    The stem-and-leaf plot is complete.
    ::干叶地已经完工了

    Use this data set to answer the following questions.
    ::使用此数据集回答下列问题。

    22, 23, 24, 25, 33, 34, 40, 51, 52, 52, 60, 61, 62

    Example 3
    ::例3

    Draw a stem-and-leaf plot.
    ::绘制干叶图。

    Stem Leaves 2 2 , 3 , 4 , 5 3 3 , 4 4 0 5 1 , 2 , 2 6 0 , 1 , 2

    ::StemLeaves22,3,4,533,44051,2,260,1,2

    The stem-and-leaf plot is complete.
    ::干叶地已经完工了

    Example 4
    ::例4

    Consider the stem-and-leaf plot from Example 1. Which stem would have the most leaves?
    ::考虑一下例1中的干叶草, 哪一种树叶叶最多?

    The most leaves are in the 20’s.
    ::最多叶子在20年代。

    Example 5
    ::例5

    Consider the stem-and-leaf plot from Example 1. Which stem would have the least leaves?
    ::考虑一下例1中的干叶草块,哪个干叶叶叶最少?

    The least leaves are in the 40’s.
    ::最少的叶子在40年代。

    Review
    ::回顾

    Use each situation to answer the following questions.
    ::利用每一种情况回答下列问题。

    Students spent the following total minutes on homework last Thursday evening:
    ::学生们在上周四晚上做功课 总共花了以下几分钟时间:

    45, 45, 40, 43, 36, 50, 60, 55, 55, 45, 60, 63, 90, 75, 80

    1. Make a stem-and-leaf plot that represents the data.
    ::1. 绘制代表数据的干叶图。

    2. Which stem has the greatest number of values?
    ::2. 哪个干线的值最多?

    3. Which stem has the least number of values?
    ::3. 哪个干点的值最少?

    4. What can you interpret from the plot?
    ::4. 你能从阴谋中解释什么?

    5. Why is it necessary to show intervals for which there was no data?
    ::5. 为什么要显示没有数据的间隔?

    A hybrid car and a gasoline-only car filled up on the same days of the month. The drivers recorded the gasoline costs for the two cars.
    ::司机记录了两辆汽车的汽油费用。

    Hybrid:
    ::混合 :

    $17, $24, $19, $21, $10, $12, $15, $20, $6, $16

    Gasoline-Only:
    ::仅汽油 :

    $34, $27, $15, $31, $29, $27, $24, $14, $35, $28

    6. Create a double stem-and-leaf plot to represent this data.
    ::6. 创建双干叶图以显示这一数据。

    7. Which stem has the greatest number of values for a hybrid?
    ::7. 混合体的值是多少?

    8. Which stem has the greatest number of values for a gasoline-only car?
    ::8. 哪个干线的汽油专用汽车的值最高?

    9. What can you conclude from your stem-and-leaf plot?
    ::9. 你能从你的干叶图中得出什么结论?

    Kelly earned the following amounts of money babysitting:
    ::Kelly当保姆赚了以下金额的钱:

    $30.00, $10.00, $15.00, $20.00, $18.00, $22.00, $35.00, $40.00 and $58.00.
    ::30.00美元、10.00美元、15.00美元、200.00美元、18.00美元、22.00美元、35.00美元、400.00美元和58.00美元。

    10. Make a stem-and-leaf plot that represents the data.
    ::10. 绘制代表数据的干叶图。

    11. Which stem has the greatest number of values?
    ::11. 哪个干部的数值最多?

    12. Which stem has the least number of values?
    ::12. 哪个干部的数值最少?

    13. What can you interpret from the plot?
    ::13. 你能从阴谋中解释什么?

    Review (Answers)
    ::回顾(答复)

    Click to see the answer key or go to the Table of Contents and click on the Answer Key under the 'Other Versions' option.
    ::单击可查看答题键, 或转到目录中, 单击“ 其他版本” 选项下的答题键 。