题目
Twenty children were asked to estimate the height of a particular tree. Their estimates, in metres, were as follows.
| 4.1 | 4.2 | 4.4 | 4.5 | 4.6 | 4.8 | 5.0 | 5.2 | 5.3 | 5.4 |
| 5.5 | 5.8 | 6.0 | 6.2 | 6.3 | 6.4 | 6.6 | 6.8 | 6.9 | 19.4 |
(a) Find the mean of the estimated heights.
(b) Find the median of the estimated heights.
(c) Give a reason why the median is likely to be more suitable than the mean as a measure of the central tendency for this information.
题目中文翻译
请 20 名儿童估计某棵树的高度。他们的估计值如下，单位为米。
| 4.1 | 4.2 | 4.4 | 4.5 | 4.6 | 4.8 | 5.0 | 5.2 | 5.3 | 5.4 |
| 5.5 | 5.8 | 6.0 | 6.2 | 6.3 | 6.4 | 6.6 | 6.8 | 6.9 | 19.4 |
(a) 求这些高度估计值的平均数。
(b) 求这些高度估计值的中位数。
(c) 给出一个理由，说明对于这些信息，中位数为什么可能比平均数更适合作为集中趋势的度量。
原卷通用作答要求
Answer all questions. You should use a calculator where appropriate.
You must show all necessary working clearly; no marks will be given for unsupported answers from a calculator.
Give non-exact numerical answers correct to 3 significant figures, or 1 decimal place for angles in degrees, unless a different level of accuracy is specified in the question.
请回答所有题目。适当时应使用计算器。必须清楚展示所有必要的计算过程；仅给出计算器答案而没有过程，不予评分。除非题目另有精度要求，非精确数值答案保留 3 位有效数字，以度为单位的角度保留 1 位小数。
解答
(a)
解法一
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二十个估计值求和后除20。
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(b)
解法一
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已排序20项，中间第10、11项取平均。
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(c)
解法一
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结合树高说明19.4这个异常估计对均值的影响。
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The unusually large estimate of pulls the mean estimated tree height upwards, whereas the median is much less affected by this extreme value.