11.2 中中

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  Mrs. Lee wants to find the median score in her mathematics class. She has organized her students' scores into the following table.
  ::李夫人想在数学课上找到中分,她将学生的分数安排在下表。

  Mrs Lee's Class Test Results

  Student	Test Score (%)
  AS	89
  AS	91
  BC	87
  CS	77
  播放段落 FR ::联邦联邦联邦	72
  JW	59
  ML	76
  MY	68
  ST	91
  SR	83
  VS	81
  ZS	73

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  How can Mrs. Lee figure out what the median score on the test is?
  ::李太太怎么知道测试的中位分数是多少?

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  In this concept, you will learn how to calculate median.
  ::在这个概念中,你会学会如何计算中位数。

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  Calculating Median
  ::计算中位数

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  Data is a set of numerical or non-numerical information. Data can be analyzed in many different ways. In this concept you will analyze numerical data using the median.
  ::数据是一组数字信息或非数字信息。数据可以多种不同方式分析。在这个概念中,您将使用中位数分析数字数据。

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  Median is a numerical value that represents the middle term in a data set . When ordered sequentially, the value that is in the middle is the median. 
  ::中间值是一个数字值,代表数据集中的中期值。如果按顺序排列,中间值为中值。

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  To calculate the median, first order the numbers from smallest to largest. Then, find the number that is in the middle. This number is the median.
  ::要计算中位数, 请先将数字从最小到最大排序。 然后, 找到中间的数字。 此数字是中位数 。

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

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  Find the median for the set of data: 47, 56, 51, 45, and 41.
  ::查找数据集的中位数:47、56、51、45和41。

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  First, arrange the numbers from smallest to largest.
  ::首先,安排从最小到最大的数字。

  41, 45, 47, 51, 56

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  Next, find the middle number. There are five numbers in this set, so the middle number is the third term, 47. 
  ::接下来,找到中间数字。这组有五个数字, 所以中间数字是第三个,47。

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  The answer is the median is 47.
  ::答案是中位数是47

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  Examples
  ::实例

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  Example 1
  ::例1

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  Earlier, you were given a problem about Mrs. Lee and her students' test scores.
  ::之前,你得到一个问题 李太太和她的 学生考试成绩。

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  Mrs. Lee has given her students a math test and wants to calculate the median score. She has organized her student's data into the following table.
  ::李夫人给学生做了数学测试,想计算中位分数。她将学生的数据整理成下表。

  Mrs. Lee's Class Test Results

  Student	Test Score (%)
  AS	89
  AS	91
  BC	87
  CS	77
  播放段落 FR ::联邦联邦联邦	72
  JW	59
  ML	76
  MY	68
  ST	91
  SR	83
  VS	81
  ZS	73

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  First, organize the data from smallest to largest.
  ::首先,组织从最小到最大的数据。

  59, 68, 72, 73, 76, 77, 81, 83, 87, 89, 91, 91
  

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  Next, find the middle term.
  ::下一个,找到中期。

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  There are 12 numbers in this set so the middle number is between the sixth and seventh term, 77 and 81. To find the term that is between 77 and 81, add the numbers together and divide by 2.
  ::这一组有12个数字,所以中间数字在第六学期和第七学期之间,77学期和81学期之间。 要找到77学期和81学期之间,将数字加在一起,除以2。

    $\begin{array}{r}77+81=158\end{array}$

    $\begin{array}{r}158÷2=79\end{array}$  

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  The answer is the median math test score of Mrs. Lee's class is 79%.
  ::答案是李太太班级的中位数学测试分数是79%。

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  Example 2
  ::例2

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  The chart below shows the daily temperature in San Diego for the first seven days in August. Calculate the median temperature.
  ::以下图表显示了圣地亚哥8月份头七天的每日温度。计算中位温度。

  San Diego Temperatures in August

  Date:	Temperature:
  Sunday 8/1	$\begin{array}{r}{88}^{\circ }F\end{array}$
  Monday 8/2	$\begin{array}{r}{83}^{\circ }F\end{array}$
  Tuesday 8/3	$\begin{array}{r}{87}^{\circ }F\end{array}$
  Wednesday 8/4	$\begin{array}{r}{89}^{\circ }F\end{array}$
  Thursday 8/5	$\begin{array}{r}{82}^{\circ }F\end{array}$
  Friday 8/6	$\begin{array}{r}{79}^{\circ }F\end{array}$
  Saturday 8/7	$\begin{array}{r}{87}^{\circ }F\end{array}$

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  First, arrange the temperatures from smallest to greatest.
  
  ::首先,从最小到最大的温度

  79, 82, 83, 87, 87, 88, 89

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  Next, find the middle number. There are seven numbers in this set, so the middle number is the fourth term, 87. 
  ::接下来,请找到中间数字。 这个组里有七个数字, 所以中间数字是第四学期, 87。

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  The answer is the median is  $\begin{array}{r}{87}^o\end{array}$ F.
  ::答案是中位数是87oF。

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  Example 3
  ::例3

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  Find the median of the following data set.
  ::查找以下数据集的中位数。

  $\begin{array}{r}12,14,15,16,18,20\end{array}$

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  First, arrange the numbers in order. In this case, they are already ordered from smallest to largest.
  ::首先,按顺序排列数字。在这种情况下,它们已经从最小点到最大点。

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  Next, find the middle term. There are six numbers in the set, so the middle number is between the third and fourth terms, 15 and 16. To find the term that is between 15 and 16, we add the numbers together and divide by 2.
  ::找到中期。 集中共有六个数字, 所以中间数字在第三和第四, 15和16之间, 为了找到15和16之间的术语, 我们将数字加在一起, 并除以2。

    $\begin{array}{r}15+16=31\end{array}$

    $\begin{array}{r}31÷2=15.5\end{array}$

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  The answer is the median is 15.5.
  ::答案是中位数是15.5

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  Example 4
  ::例4

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  John wants to know his median quiz grade based on the following quiz scores.
  ::约翰想知道他的中位测验成绩 根据以下的测验分数

  78, 90, 83, 88, 67, 90, 84, 69, 56

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  First, order the numbers from smallest to largest.
  ::首先,将数字从最小到最大顺序排列。

  56, 67, 69, 78, 83, 84, 88, 90, 90

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  Next, find the middle number. There are nine numbers in this set, so the middle number is the fifth term, 83. 
  ::接下来,找到中间数字。这组有九个数字, 所以中间数字是第五,83。

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  The answer is the median is 83.
  ::答案是中位数是83

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  Example 5
  ::例5

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  Find the median of the following data set.
  ::查找以下数据集的中位数。

  12, 14, 16, 11, 19, 12, 15, 16, 17, 22, 21, 23

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  First, arrange the numbers from least to greatest. 
  ::首先,从最少到最大的数字排列。

  11, 12, 12, 14, 15, 16, 16, 17, 19, 21, 22, 23

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  Next, find the middle number. There are 12 numbers in this set, so the middle number is between the sixth and seventh term, 16 and 16. Since these two terms are the same, this number is the median.
  ::接下来请找到中间数字。 这个组中有12个数字, 所以中间数字在第六学期和第七学期之间, 16和16, 因为这两个词相同, 这个数字是中位数 。

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  The answer is the median is 16.
  ::答案是中位数是16

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  Review
  ::回顾

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  Find the median for each set of numbers. Round your answer to the nearest hundredths place where needed.
  ::查找每组数字的中位数。 将您的答案四舍五入到最接近的百位点 。

  1. 2, 1, 3, 4, 2, 1, 5, 6, 7, 2, 3
  2. 11, 12, 17, 18, 21, 12, 13, 13
  3. 20, 22, 21, 24, 25, 20, 19
  4. 18, 17, 19, 21, 22, 20, 18, 17
  5. 19, 29, 39, 49, 59, 69, 79, 89
  6. 4, 5, 4, 5, 3, 3, 2, 3, 3, 2
  7. 6, 7, 8, 3, 2, 4
  8. 11, 10, 9, 13, 14, 16
  9. 21, 23, 25, 22, 22, 27
  10. 27, 29, 29, 32, 30, 32, 31
  11. 34, 35, 34, 37, 38, 39, 39
  12. 43, 44, 43, 46, 39, 50
  13. 122, 100, 134, 156, 144, 110
  14. 224, 222, 220, 222, 224, 224
  15. 540, 542, 544, 550, 548, 547

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  Review (Answers)
  ::回顾(答复)

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  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 。

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  Resources
  ::资源