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Medical Statistics(医学统计学)

  1. In one-way ANOVA, if the treatment factors have no effect, there should be ( )

  2. A:F=1 B:F>1 C:F<1.96 D:F=0
    答案:reject H0since there is evidence of a treatment effect.
  3. To reflect the change of hepatitis A incidence rate in a city for 5 consecutive years, which type of graph should we select? ( )

  4. A:line chart B:percentage bar chart C:histogram D:bar chart
    AI参考:正确答案是D: bar chart(条形图)。条形图适合展示不同类别的数据之间的对比关系,可以直观地反映出数据的增减变化趋势。题目中描述的是连续5年的肝病A发病率的变化情况,所以应该选择条形图来展示。选项A、B、C都不符合题意。因此,答案为D。'
  5. In a clinical trial study, the curative effect is divided into four levels: "cured, markedly effective, effective and ineffective". Now, to compare the treatment effect between the test group and the control group, the appropriate statistical method is ( )

  6. A:Chi square test for independent four fold table B:Wilcoxon rank sum test C:Fisher exact test D:Contingency chi square test
    答案:Wilcoxon Rank Sum test (Mann-Whitney U test)
  7. When comparison of mean values of two samples, if the test results show P>0.05, it means ( )

  8. A:the difference between the two population means is large B:do not support the conclusion that the two populations are different C:the difference between the two population means is small D:Support the conclusion that the two populations are not different
    答案:比较AI参考:当两个样本的均值进行比较时,如果测试结果显示P>0.05,这意味着:D:支持两个总体差异不大的结论。解释:P值是用来衡量假设检验结果可信度的统计量,P值越大,说明原假设(即两个总体之间没有差异)的可信度越高。如果P值大于0.05,则说明两个总体之间的差异并不显著,也就是说不能支持原假设。因此,选项D“支持两个总体差异不大的结论”是正确的。选项A和B都过于绝对,选项C则与题目中的信息不符。'
  9. Let the variable of paired samples be X1 and X2, then the rank sum test of paired data is ( )

  10. A:sort X1 and X2 from small to large B:sort the difference between X1 and X2 from small to large C:sort by X1 and X2 from small to large respectively D:sort the absolute value of the difference between X1 and X2 from small to large
    答案:2, 3AI参考:正确答案是D:sort the absolute value of the difference between X1 and X2 from small to large。对配对样本变量X1和X2进行秩和检验时,需要将X1和X2之间的差值的绝对值从小到大排序。因此,选项D是正确的。选项A、B和C都不正确,因为它们没有考虑到对差值进行排序,而是分别对X1和X2进行排序。'
  11. Random error refers to ( )

  12. A:error caused by improper population selection B:error caused by inaccurate measurement C:error caused by accidental factors D:error caused by operation error
    答案:正确AI参考:正确答案是D:random error,即“随机误差”。在数据收集过程中不可避免会出现误差,其中随机误差是最常见的一种,它是由许多不可预测的因素引起的,如抽样误差、测量误差、误差累积等。系统误差是有规律的误差,而记录误差是由于记录过程中出现的错误,这些都是可以被分析和解决的。因此,根据题目描述,最合适的答案是D选项:随机误差。'
  13. The least square estimation of regression coefficient is ( )

  14. A:vertical distance from each point to y mean straight line B:horizontal distance from each point to the x-mean straight line C:horizontal distance from each point to the x-axis D:vertical distance from each point to regression straight line
    AI参考:正确选项是D:vertical distance from each point to regression straight line,即回归直线的垂直距离。最小二乘法估计回归系数,是将每个点与回归直线之间的垂直距离作为最小化误差的依据,从而得到回归系数。因此,选项D是正确的答案。其他选项A、B、C都与最小二乘法的原理不符。'
  15. Each observation value is added (or subtracted) by the same number not equal to 0, then ( )

  16. A:both unchanged B:mean unchanged, standard deviation changed C:mean changed, standard deviation unchanged D:both changed
    AI参考:正确选项是【B:mean unchanged, standard deviation changed】。根据题目描述,每个观测值都被加上(或减去)了相同的非零数字,因此平均值不变,标准差改变。这是因为平均值是所有观测值之和除以观测值的个数,而标准差则是所有观测值与平均值的差的平方的平均值的平方根。当观测值被加上(或减去)非零数字时,它们的绝对值会增加(或减少),但它们的相对大小不变,因此平均值不变。但是,这些绝对值的和会增加(或减少)总和,从而导致标准差改变。因此,选项B是正确的。'
  17. Assuming that the mean height of a group of 7-year-old boys is 110cm, the standard deviation is 5cm, the mean weight of the same group is 25kg, and the standard deviation is 3kg, the conclusion of comparing variation between the two variable is ( )

  18. A:the units are different and cannot be compared. B:the variation degree of height is equal to that of weight. C:the variation degree of height is less than that of weight. D:the variation degree of height is greater than that of weight.
    AI参考:正确答案是D:the variation degree of height is greater than that of weight.。根据题目中给出的身高平均值和标准差,可以得出身高变量的变化程度大于体重变量。因此,选项D是正确的结论。选项A和B都是错误的,因为两个变量的单位不同,不能直接进行比较;选项C也是错误的,因为题目中没有给出身高和体重之间的具体关系,无法确定它们之间的变化程度大小。'
  19. the purpose of hypothesis test is ( )

  20. A:test whether the population parameters are different B:test whether the sample statistics are different C:test the accuracy of parameter estimation D:test whether the sample statistics are different from the population parameters

  21. When do regression analysis for two groups of data. The group with larger linear regression coefficient B represents ( )

  22. A:The R square may be large or small B:Large coefficient of determination C:It is more likely that the test is significant D:It is more likely that the two variables are closely related.

  23. The purpose of calculating standardized mortality is ( )

  24. A:facilitate the comparison of mortality rates in different regions B:reducing sampling errors in mortality estimates C:eliminate the impact of different internal composition in different regions D:reducing bias in mortality estimates
    AI参考:正确答案是A:facilitate the comparison of mortality rates in different regions。计算标准化死亡率的目的在于便于不同地区死亡率之间的比较,因此选项A是正确的。选项B、C、D虽然也与死亡率有关,但不符合题目要求。'
  25. Compared with the median, the arithmetic mean is characterized by ( )

  26. A:more suitable for skew distribution data B:larger sampling error C:not susceptible to extreme values D:be able to make full use of data information
    AI参考:正确选项是D:be able to make full use of data information算术平均数能够充分利用数据信息,而中位数更适合于偏态分布数据。因此,算术平均数能够更好地利用数据信息,而不是受到极端值的影响或具有更大的抽样误差。'
  27. If one of the actual numbers in the four grid table is 0, then ( )

  28. A:Chi square test correction is not allowed. B:It is not yet possible to decide whether the Chi square test can be performed or not. C:Chi square test correction must be used D:It is certain that the Chi square test correction can be performed
    AI参考:正确答案是【B:It is not yet possible to decide whether the Chi square test can be performed or not.】。原文中提到如果四格表中的实际数字之一为0,那么现在还不能决定是否可以进行卡方检验,因此选项B是正确的。选项A和D都是错误的,因为文中并没有提到是否允许或确定进行卡方检验的校正,而选项C也不正确,因为文中也没有提到必须使用卡方检验校正。'
  29. For group comparison of medical metrology data, compared with parametric test, the advantage of nonparametric rank sum test is ( )

  30. A:high inspection efficiency B:wide application range C:more accurate inspection results D:make full use of data and information
    AI参考:对于医学计量数据的组间比较,与参数检验相比,非参数秩和检验的优势是( )。答案:D:充分利用数据和信息。解释:非参数秩和检验是一种不考虑数据分布的假设检验方法,它更注重数据的实际表现,因此可以充分利用数据中的信息,而不仅仅是基于样本统计量的计算。相比之下,参数检验更注重数据的统计特性,可能会忽略一些重要的信息。因此,答案为D:充分利用数据和信息。'
  31. For the comparison of measurement data, the possible result of nonparametric analysis under the condition of meeting the parameter method is ( )

  32. A:reduce Type II errors B:add Type II error C:add Type I error D:reduce Type I errors

  33. Which of the following data can be fully described by means of mean and standard deviation? ( )

  34. A:positive skew distribution B:normal distribution and approximate normal distribution C:symmetric distribution D:negative skew distribution
    AI参考:正确答案是B:normal distribution and approximate normal distribution。平均数和标准差可以全面描述正态分布和近似正态分布的数据。A选项描述的是正偏态分布,D选项描述的是负偏态分布,这两者都需要结合偏态系数来分析。C选项对称分布指的是左右两侧数值大致相等,并不涉及平均数和标准差。因此,只有B选项中的数据可以用平均数和标准差来全面描述。'
  35. In ANOVA, when p<0.05, ( )

  36. A:It can be considered that the mean of each population is not equal B:It can be considered that the mean values of all populations are unequal or not all equal C:It can be considered that the mean of each sample is not equal D:The above are not correct
    AI参考:正确选项:【B:It can be considered that the mean values of all populations are unequal or not all equal 】在ANOVA中,当p<0.05时,可以考虑所有种群平均值不等或不全相等,所以选项B是正确的。选项A、C、D都不完全准确。'
  37. Coefficient of variation is mainly used for ( )

  38. A:Measurement accuracy B:Measure the degree of variation of skew distribution C:Compare the variation degree of different measurement indicators D:Measure the variation degree of normal distribution

  39. Cured, markedly effective, improved and ineffective belong to ( )

  40. A:none of the above B:measurement data C:count data D:grade data
    AI参考:答案:D推理过程:四个选项都是描述数据的形式,而根据常识可知,有效、显著有效、改善和无效是对治疗效果的分级,所以应选D。答案D是最贴切的。题干所给选项是客观事实。AC不考虑现实因素。B不恰当。答案与预期完全吻合。故答案选D。这句话的意思是“无效、明显有效、改善和无改变属于评估数据” ,对应的是治疗效果的评估结果。而None of the above和上述都不属于的情况是不符合常识的,应该排除;而测量数据(Measurement data)指的是直接从测量仪器得到的数字,没有体现出分级;计数数据(Count data)是指观察结果按性质分类或排列顺序,得到的分类数据,也不符合语境。所以,正确答案只能是D:grade data。'
  41. When the difference between the two samples is statistically significant, the greater the p value is, the greater the ( )

  42. A:the more reason to think that the mean values of the two populations are different B:the greater the difference between the two population means C:The more reason to think that the mean values of the two samples are different D:The greater the difference between the two sample means
    AI参考:正确选项:C:The more reason to think that the mean values of the two samples are different 。根据题目描述,当两个样本之间的差异在统计学上具有显著性时,p值越大,意味着认为两个样本的均值不同的理由越多。因此,选项C是正确的。选项A和B与题目描述不符;选项D则将样本均值混淆为总体均值,也是错误的。'
  43. The basic idea of the rank sum test for paired samples is that if the test hypothesis is true, ( )

  44. A:the absolute values of positive and negative rank sums are equal B:the absolute values of positive rank sum and negative rank sum differ greatly C:the above are all wrong D:the absolute values of positive and negative rank sums do not differ greatly
    AI参考:正确选项是D:the absolute values of positive and negative rank sums do not differ greatly。对配对样本秩和检验的基本思想是,如果原假设成立,则正负秩和的绝对值不会相差很大。因此,答案为D。'
  45. Correlation and regression analysis were carried out for two numerical variables at the same time, correlation coefficient R was statistically significant (p<0.05), then ( )

  46. A:Regression coefficient B statistically significant B:Not sure if Regression coefficient B is statistically significant C:None of the above D:Regression coefficient B not statistically significant
    AI参考:正确选项是【D:Regression coefficient B not statistically significant】。根据题干描述,在进行两个数值变量的相关性和回归分析时,相关系数R具有统计显著性(p<0.05),因此回归系数B也应该具有统计显著性。但选项中只有D符合这一要求,因此D是正确答案。A和B选项都是错误的,因为它们都暗示了回归系数B具有统计显著性,而C选项则完全错误,因为回归系数B不具有统计显著性是不正确的。'
  47. There is no definite value at the large end of a set of medical data, and the applicable statistical index to describe its center tendency is ( )

  48. A:Median B:Geometric mean C:Percentile D:Mean
    AI参考:正确答案是A:Median(中位数)。在一组数据中,中位数是位于中间位置的数值,其可以反映数据的中心趋势,即对于一组医疗数据,由于数据本身没有固定的数值大小,所以没有确定的数值,只能描述其中心趋势,选项A为中位数,因此为正确答案。选项B、C、D分别为几何平均数、百分位数和平均数,这些指标都可以用来描述数据的中心趋势,但不适用于描述医疗数据的中心趋势。'
  49. To reduce the class II error of hypothesis test, the method that should be used is ( )

  50. A:Reduce the random error of measurement B:Reduce class I error C:Increase sample size D:improve the test bound
    AI参考:正确答案是C:增加样本量(Increase sample size)。为了减少假设检验中的第二类错误,应该采用的方法是增加样本量,而不是减少随机误差、减少第一类错误或改善测试边界。因此,选项C是正确答案。'
  51. Normally distributed data usually have ( )

  52. A:mean = geometric mean B:mean > median C:mean = median D:mean < median

  53. The smoking rate of men is 10 times that of women, which is ( )

  54. A:rate B:standardization rate C:component ratio D:relative ratio

  55. When doing the ANOVA of multiple group mean comparison. If P < 0.05, ( )

  56. A:block analysis of variance B:t-test of two means C:homogeneity test of variance D:q test
    AI参考:正确选项是【C:homogeneity test of variance】。当进行多组均值比较的ANOVA分析时,如果P值小于0.05,则需要进行方差齐性检验(C选项),以确定各组数据是否具有相同的分布,这是进行进一步比较的前提。而选项A、B和D分别涉及了独立样本t检验、配对样本t检验和q检验,与题目要求不符。'
  57. Compare the four percentages, if one theoretical number is less than 5, but greater than 1, and the others are greater than 5, then ( )

  58. A:only correction Chi square test can be performed B:no Chi square test can be performed C:a reasonable combination must be made first D:it is not necessary to correct
    AI参考:正确答案是D: it is not necessary to correct。题目中给出的四个百分比中,其中一个理论数值小于5但大于1,而其他三个都大于5。在这种情况下,不需要进行校正卡方检验,因为这四个百分比之间的差异不足以引起显著性差异。因此,选项D是正确的。'
  59. The basic step of medical statistics is ( )

  60. A:Investigation, data collection, data processing and data analysis B:Statistical data collection, data processing, statistical description and statistical inference C:Design, collect, process and analyze data D:Design, statistical description, statistical inference, statistical chart
    AI参考:正确答案是C:设计,收集,处理和分析数据。医学统计的基本步骤包括设计、数据收集、数据处理和数据分析。选项C中的“设计,收集,处理和分析数据”恰好涵盖了这些步骤,因此是正确答案。选项A中的“调查”和“数据分析”不是医学统计的基本步骤;选项B中的“统计描述”和“统计推断”是医学统计中的重要步骤,但不是基本步骤;选项D中的“统计图表”不是医学统计的基本步骤。因此,选项C是唯一正确的答案。'
  61. Indicates the average level of serological titer data, ____is commonly used ( )

  62. A:Geometric mean B:Median C:Arithmetic mean D:Range

  63. To compare the positive reaction rates of the two groups, if the sample size is very small (e.g. n1<10, n2<10), then ( )

  64. A:Fisher exact test B:Chi square test correction for two independent samples four fold table C:Chi square test for paired samples D:Chi square test for two independent samples four fold table
    AI参考:正确答案是D:Chi square test for two independent samples four fold table。这是一个关于两组样本阳性反应率比较的问题,当样本量非常小(例如n1小于10,n2小于10)时,应该使用卡方检验(Chi square test)来比较两组样本的阳性反应率。卡方检验是一种用于比较两个或多个样本的计数数据的统计方法,适用于独立样本的情况。因此,选项D是正确的答案。选项A和B都是卡方检验的修正版本,但是适用于特定的表格数据情况,而选项C则适用于配对样本的情况。因此,正确答案是D。'
  65. Which the following observation results belong to ordinal data: ( )

  66. A:systolic blood pressure measurement B:pulse number C:Length of stay D:degree of illness
    AI参考:正确答案是B: pulse number。脉冲数量属于有序数据,因为它可以被排序和比较。而其他选项如血压、住院时间和病情程度都属于数值型数据,无法进行排序和比较。因此,选项B是正确的。'
  67. For the population with normal skew distribution, when the sample size is large enough, the distribution of the sample mean is approximately ( )

  68. A:normal distribution B:negative skew distribution C:t distribution D:positive skew distribution

  69. Which of the following statistical chart that ordinates must start from 0 ( )

  70. A:scatter chart B:straight bar chart C:percent straight bar chart D:Ordinary line chart

  71. Value of coefficient of variation ( )

  72. A:must be greater than 1 B:it must be larger than the standard deviation C:can be greater than 1 or less than 1 D:it must be smaller than the standard deviation
    AI参考:正确选项是【C:can be greater than 1 or less than 1】。选项A和D表述错误,选项B和D虽然都提到了标准差,但是并没有明确指出标准差与变异系数之间的关系。因此,C选项“变异系数可以大于1或小于1”是正确的表述。变异系数的范围通常在0到1之间,但也可能大于1或小于0,这取决于数据的分布和测量方法。因此,C选项是符合实际情况的。'
  73. To describe the average level of a group of skew distribution data, which should generally be selected ( )

  74. A:Geometric mean B:Arithmetic mean C:Mean D:Median
    AI参考:描述一组偏态分布数据的平均水平,通常应该选择(B)算术平均数。算术平均数是表示数据集中位置的指标,适用于偏态分布的数据。它能够反映数据的整体趋势,并能够有效地将数据集中趋势呈现出来。因此,对于描述一组偏态分布数据的平均水平,算术平均数是一个合适的选择。其他选项中,几何平均数通常用于求一组数据的乘积,而中位数则对于偏态分布的数据可能不太适用。因此,正确答案是B。'
  75. For data with approximate normal distribution, the index to be used to describe the degree of variation is ( )

  76. A:Range B:Inter-quartile range C:Standard deviation D:Coefficient of variance
    AI参考:对于近似正态分布的数据,用来描述变异程度的指标是:D:Coefficient of variance,即变异系数。变异系数是将标准差与平均值的乘积用于表示数据的离散程度。对于正态分布的数据,通常使用标准差来描述其变异程度,但是在一些近似正态分布的数据中,由于数据的分布中心在平均值附近,使用标准差可能无法准确地描述数据的离散程度。因此,使用变异系数结合平均值一起使用可以更好地描述这种数据的离散程度。因此,本题的正确选项是D:Coefficient of variance。'
  77. The range of 95% medical reference range of an indicator indicates ( )

  78. A:The detection index is within this range, and the probability of judging "normal" is greater than or equal to 95% B:95% of the "abnormal" population are outside this range C:The detection index is within this range, and the probability of judging "abnormal" is greater than or equal to 95% D:95% of the "normal" population is in this range
    AI参考:正确答案是A:The detection index is within this range, and the probability of judging "normal" is greater than or equal to 95%。根据题干中的描述,95%的医学参考范围表示检测指标在这个范围内,判断“正常”的概率大于等于95%。因此,选项A符合题意。选项B、C、D都与题干描述不符。'
  79. Compared with the mean of the two samples, the difference was statistically significant by t-test. The smaller the p value, the more reason to think that the difference between the two sample means is greater. ( )

  80. A:对 B:错
    AI参考:答案是B:错。根据题目描述,通过t检验,两个样本的平均值之间的差异具有统计学意义上的显著性,但是小p值并不意味着更有理由认为两个样本的平均值之间的差异更大。这是因为p值只是一个概率值,用于表示结果在经过随机化试验或分析后发生的可能性大小,并不直接反映实际的数据大小。因此,应该对题目进行修正为:“即使p值很小,我们也不能确定两个样本的平均值之间的差异是否更大。”所以答案是B。'
  81. As the sample observation results are uncertain, the population cannot be inferred from the sample. ( )

  82. A:错 B:对
    AI参考:正确答案是【错】。这个判断题的意思是,由于样本观察结果的不确定性,不能从样本推断出总体。在统计学中,样本是从总体中随机抽取的,其结果只能代表总体的一部分信息,不能完全代表总体。因此,如果样本观察结果不确定,那么就不能从样本推断出总体的情况。所以,这个判断题的答案是“错”。'
  83. When drawing any figure, the starting scale of the vertical coordinate must be "0". ( )

  84. A:错 B:对
    AI参考:正确答案是【B:对】。在绘制任何图形时,垂直坐标系的起始比例必须为“0”。这是因为在计算机图形学中,坐标系的原点通常被定义为零点,用于表示图形的基本位置。因此,选项B是正确的。'
  85. In the experimental design, the estimated sample size should be as much as possible if the economy allows. ( )

  86. A:对 B:错
    AI参考:对。根据实验设计的原则,如果经济条件允许,估计样本大小应该尽可能大。这意味着需要更多的数据来确保实验结果的可靠性和有效性。因此,答案为A:对。'
  87. When the mean of the two samples is compared, if P > 0.05 after t-test, it indicates that the mean of the two populations in the comparison group is equal. ( )

  88. A:错 B:对
    AI参考:答案是B:对。根据t检验的结果,如果P值大于0.05,说明两个样本的平均值是相等的。因此,这个判断题是正确的。'
  89. When the observation units are the same, standard deviation and coefficient of variance are used to express the dispersion degree of the two groups of data, and the conclusion is exactly the same.( )

  90. A:对 B:错
    AI参考:答案是B:错。当观察单位相同时,标准差和变异系数是用来表达两组数据分散程度的,但得出的结论是不同的。标准差可以用来比较两个或多个独立样本的分散程度,而变异系数则考虑了数据可能的规模效应,更适合于比较不同规模样本的分散程度。所以这个判断题是错误的。'
  91. The main content of statistical work is statistical analysis of data. ( )

  92. A:对 B:错

  93. The 95% confidence interval of the difference between the two means can also reflect whether the difference between the two means is statistically significant. ( )

  94. A:错 B:对

  95. The larger the correlation coefficient r is, the stronger the correlation is. ( )

  96. A:错 B:对
    AI参考:正确答案是B:对。根据题目描述,当r值越大时,表示相关性越强。因此,选项B是正确的。'
  97. The smaller the p value, the smaller the probability of rejecting the H0. ( )

  98. A:对 B:错
    AI参考:答案:B:错。解释:在假设检验中,p值越小,拒绝零假设H0的结论就越不能被接受,但是并不能简单地得出概率越小就说明某个推断不正确,应该谨慎解释这个结论。这个选项考虑不够全面,所以答案是B,即错误的。'

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