2021 Medical Statistics(Sun Yat-sen University) 最新满分章节测试答案

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本课程起止时间为:2021-02-25到2021-05-21
本篇答案更新状态:已完结

Chapter1 Introduction and Basic Concepts Introduction and Basic Concepts

1、 问题:Which one of the following symbols could represent a population parameter?
选项：
A:‍
B:x
C:p
D:π
E:S
答案: 【π】

2、 问题:Which of the following statements about probability is WRONG?
选项：
A:Probability is the measure of the likelihood that an event will occur.
B:The value of a probability lies in the interval of [0,1].
C:The frequency of an event E is exactly the probability of the event E.
D:An event with probability of 0 is called an impossible event.
E:In reality, probability is difficult to obtain.
答案: 【The frequency of an event E is exactly the probability of the event E.】

3、 问题:To know the average level of lung capacity of Grade 2015 students at the Sun Yat-sen University, an investigator measured the lung capacity of students in 30 sampled classes of Grade 2015 from this University. The whole collection of the measured lung capacity data is a      .
选项：
A:sample
B:population
C:variable
D:statistic
E:parameter
答案: 【sample】

4、 问题:A Statistic is        
选项：
A:equal to a parameter of the population.
B:an exact characteristic of the population.
C:an index calculated based on all data of the population.
D:obtained after studying all the individuals in the population.
E:calculated based on a sample.
答案: 【calculated based on a sample.】

5、 问题:To make a statistical inference for the population from a sample, the sample should be:        
选项：
A:the most typical part of the population.
B:any part of the population.
C:the most meaningful part of the population.
D:the most explicit part of the population.
E:a part randomly selected from the population.
答案: 【a part randomly selected from the population.】

Chapter2 Descriptive Statistics Descriptive Statistics

1、 问题:The Statistic in Statistics is:         ‍
选项：
A:obtained from the data of the population.
B:reflection of the statistical characteristics of the population.r
C:an index calculated based on all data of the population.
D:obtained after studying all the individuals in the population.
E:a statistical indicator calculated based on the sample.
答案: 【a statistical indicator calculated based on the sample.】

2、 问题:A researcher measured 50 patients’ weights. There were 13 patients less than 50Kg, and 17 patients over 70Kg, with the rest weighing between 50 and 70Kg. Which type of variable is used by the researcher?
选项：
A:quantitative variable
B:categorized variable
C:ordinal variable
D:binary variable
E: nominal variable
答案: 【ordinal variable】

3、 问题:The conversion of variables can only be done from quantitative variables → nominal variables → ordinal variables →binary variables, which cannot be converted in an opposite direction.
选项：
A:正确
B:错误
答案: 【错误】

4、 问题:The unit of the coefficient of variation is the same as the unit of the original variable.
选项：
A:正确
B:错误
答案: 【错误】

Chapter 3 Probability and Distribution Probability and Distribution

1、 问题:Which of the following conditions could make the binomial distribution B(n, π) approximate the Poisson distribution?
选项：
A:When n is large and π approaches to 0.
B:When n®¥ .
C:When nπ or n(1-π) approaches to 0.5.
D:When n is large and π approaches to 0.5.
E:When π approaches to 0.5.
答案: 【When n is large and π approaches to 0.】

2、 问题:A certain measurement index shows a logarithmic normal distribution, which is considered as abnormal if it is too high, and which of the following should be used to calculate the range of medical reference value with a scope of 95%？
选项：
A:
B:
C:
D:
E:
答案: 【】

3、 问题:Which of the following statements about the probability is WRONG?
选项：
A:Probability is the measure of the likelihood that an event will occur.
B:Any probability takes value from the interval [0,1].
C:The frequency of an event E is exactly the probability of the event E.
D:The event with probability of 0 is called an impossible event.
E:In practice, the probability is difficult to be obtained.
答案: 【The frequency of an event E is exactly the probability of the event E.】

4、 问题:Whenλ is large enough, Poisson distribution  tends to be a normal distribution.
选项：
A:正确
B:错误
答案: 【正确】

5、 问题:For data subject to a normal distribution, the probability of a variable between 1.96 and 1.96 is 0.95.
选项：
A:正确
B:错误
答案: 【错误】

【作业】Chapter2 Descriptive Statistics Descriptive Statistics

1、 问题:
评分规则: 【


(4) Key points of discussion    – explain why need to use standardized mortality rate;   – standard population different, the standardized mortality may be different;   – important to select a proper standard population, usually people use provincial or national data   – if age-specific morality rates cross between the two cities, separate comparisons are used.
】

Chapter 4 Sampling Error and Confidence Interval Confidence Interval

1、 问题:If a t-test shows the difference between two sample means is statistically significant (P<0.05), then confidence interval of the difference between the two population means may not be        
选项：
A:(1.33, 2.59)
B:(-1.15, 6.08)
C:(-2.33, -1.00)
D:(10, 15)
E:(10, 15)
答案: 【(-1.15, 6.08)】

2、 问题:Which of the following statements correctly explains the meaning of the interval          . 
选项：
A:There is a 99% probability that the population mean falls within this interval.
B:There is a 99% probability that the sample mean falls within this interval.
C:It is the 99% confidence interval for the population mean.
D:It is the 99% confidence interval for sample mean.
E:There is a 95% probability that the population mean falls within this interval.
答案: 【It is the 99% confidence interval for the population mean.】

3、 问题:Which of the following formulas can be used to estimate the 95% confidence interval for the population mean of a normal distribution_____
选项：
A:
B:
C:
D:
E:
答案: 【】

4、 问题:For a group of given data, the relationship between 95% CI and 99% CI is that           
选项：
A:99% CI is narrower than 95% CI.
B:95% CI is narrower than 99% CI.
C:95% CI is equal to 99% CI.
D:95% CI is always 1.96 times narrower than 99% CI.
E:99% CI is always 1.96 times narrower than 95% CI.
答案: 【95% CI is narrower than 99% CI.】

5、 问题:When we intend to estimate the sample size for confidence interval of a population mean which follows a normal distribution, which of the following condition requires a larger sample size while other background remains the same? _____
选项：
A:High confidence level
B:Small variation of the individuals 
C: Poor precision
D: p is near to 1
E:p is near to zero
答案: 【High confidence level】

【作业】Chapter 3 Probability and Distribution Probability and Distribution

1、 问题:Please list the main differences among Poisson distribution，binomial distribution and normal distribution?
评分规则: 【 The differences are needed discussed from two aspects.The first aspect is application:   Poisson distribution is usually used to determine the probability of the incidence of the rare diseases. It is used in discrete variables. (1 point)Binomial distribution can be used to describe the probabilities of obtaining different number of events for n independent random experiments, each of them has only two possible outcomes with probabilities of p and 1-p. It is used in discrete variables. (1 point)Normal distribution can describe many natural phenomena and used in continuous variable. (1 point)
The second aspect is Parameter：(1) Poisson distribution has only one parameter l.(1 point)(2) Binomial distribution has two parameters n and p.(1 point)(3) Normal distribution has two parameters m ands.(1 point)
】

2、 问题:The measured values of total cholesterol in 144 normal adult males aged 30 to 45 years in a certain area approximately followed a normal distribution with a mean of 4.95 mmol/L and a standard deviation of 0.85 mmol/L. （1）Try to estimate the 95% reference value range of total cholesterol for adult males aged 30 to 45 years in this area; （2）What percentage of normal adult males with total cholesterol greater than 5.72mmol/L accounted for?