大学MOOC 商务统计(华东交通大学)1450390197 最新慕课完整章节测试答案

第一单元测试

1、单选题：
‏The general process of gathering, organizing, summarizing, analyzing, and interpreting data to assist in making effective decisions is called:​
选项：
A: statistics.
B: descriptive statistics.
C: inferential statistics.
D: levels of measurement.
答案: 【 statistics.】

2、单选题：
‌A sample is:‏
选项：
A: at least 15 observations.
B: a group of people.
C: part of a population.
D: a set of frequencies.
答案: 【 a group of people.】

3、单选题：
The main purpose of inferential statistics is to:‏‏
选项：
A: summarize data in a useful and informative manner.
B: estimate population characteristics based on a sample information.
C: determine if the data adequately represents the population.
D: gather or collect data.
答案: 【 estimate population characteristics based on a sample information.】

4、单选题：
‏To study the characteristics of loan applicants, a random sample of 50 loan applicants is selected and their annual incomes are obtained. Which level of measurement is annual income?‏
选项：
A: Nominal
B: Ordinal
C: Interval
D: Ratio
答案: 【 Ratio】

5、单选题：
‎The main purpose of descriptive statistics is to:​
选项：
A: summarize data in a useful and informative manner.
B: estimate a population characteristic based on a sample.
C: determine if the data adequately represents the population.
D: gather or collect data.
答案: 【 summarize data in a useful and informative manner.】

6、单选题：
‍A bank asks customers to evaluate the quality of drive-through service as good, average, or poor. Which level of measurement is used to measure service quality?​
选项：
A: Nominal
B: Ordinal
C: Interval
D: Ratio
答案: 【 Ordinal】

7、单选题：
The main purpose of descriptive statistics is to:‏‏
选项：
A: summarize data in a useful and informative manner.
B: estimate a population characteristic based on a sample.
C: determine if the data adequately represents the population.
D: gather or collect data.
答案: 【 summarize data in a useful and informative manner.】

8、单选题：
‎Gallup political polls ask people their political party affiliation - Democrat, Republican or Independent. Which level of measurement is used to measure party affiliation?‍
选项：
A: Nominal
B: Ordinal
C: Interval
D: Ratio
答案: 【 Nominal】

9、单选题：
‏What type of variable is: number of car accidents reported in your city?‌
选项：
A: Attribute
B: Continuous
C: Discrete
D: Qualitative
答案: 【 Discrete】

10、单选题：
‏Data measured with an ordinal scale:‎
选项：
A: can be ranked.
B: have a meaningful value of zero.
C: have meaningful differences between values.
D: are quantitative.
答案: 【 can be ranked.】

第二单元测验

1、单选题：
‍In a frequency distribution the classes must:‏
选项：
A: be mutually exclusive.
B: have a maximum of 10 observations.
C: have equal frequencies.
D: be measured on a nominal scale.
答案: 【 be mutually exclusive.】

2、单选题：
‌For a frequency distribution, the class interval is:‌
选项：
A: the class frequencies divided by two.
B: the class frequency divided by the number of observations.
C: the difference between consecutive lower class limits.
D: the number of observations in the class.
答案: 【 the difference between consecutive lower class limits.】

3、单选题：
‏For a frequency distribution, a class frequency is:‎
选项：
A: the number of observations in the class.
B: the difference between consecutive lower class limits.
C: limited to a maximum of 10 observations.
D: the total number of observations in the sample.
答案: 【 the number of observations in the class.】

4、单选题：
‎A research organization is studying the selling price of laptop computers. They selected 25 different computers for the study. To summarize the selling price with a frequency distribution and using the 2k rule, how many classes would you recommend?‍
选项：
A: 10
B: 25
C: 4
D: 5
答案: 【 5】

5、单选题：
‎For a frequency distribution, the class midpoint is:‏
选项：
A: the class interval divided by two and added to the lower limit.
B: the difference between consecutive lower limits.
C: the number of observations in the class.
D: the class frequency divided by the number of observations.
答案: 【 the class interval divided by two and added to the lower limit.】

6、单选题：
​Which of the following is not a guideline for a frequency distribution?‏
选项：
A: Avoid open-ended classes.
B: Use the 2k rule to determine the number of classes.
C: Make the lower limit of the first class a multiple of the class interval.
D: Each class should have more than 5 observations.
答案: 【 Each class should have more than 5 observations.】

7、单选题：
​To convert a frequency distribution to a relative frequency distribution:‏
选项：
A: find the difference between consecutive lower class limits.
B: divide the class frequency by the total number of observations.
C: divide the lower limit of the first class by the class interval.
D: multiple the class frequency by 100.
答案: 【 divide the class frequency by the total number of observations.】

8、单选题：
​A pie chart shows:‎
选项：
A: the frequency for each class.
B: the relative frequency for each class.
C: trends in the data.
D: the class midpoints.
答案: 【 the relative frequency for each class.】

9、单选题：
‎The difference between a histogram and a frequency polygon is:‍
选项：
A: the frequency polygon is reported as a percent, a histogram does not report percents.
B: the histogram shows frequencies while a frequency polygon shows cumulative frequencies.
C: the bars in a histogram and a frequency polygon cannot be adjacent.
D: open-ended classes can be accommodated with a frequency polygon.
答案: 【 the histogram shows frequencies while a frequency polygon shows cumulative frequencies.】

10、单选题：
‌In a cumulative frequency polygon:​
选项：
A: the class frequencies are converted to percents.
B: the cumulative frequency for the first class limit is zero.
C: we add the class frequencies starting with the first class.
D: all of the above.
答案: 【 all of the above.】

第三单元测验

1、单选题：
‌A key difference between calculating the sample mean and the population mean is:‎
选项：
A: we use  and n instead of μ and N.
B: we divide the sum of the observations by n - 1 instead of n.
C: the sample observations are ranked and the middle value is selected as the population mean.
D: there are no differences.
答案: 【 we use  and n instead of μ and N.】

2、单选题：
‏Which of the following measures of central location is affected most by extreme values?‌
选项：
A: Median
B: Mean
C: Mode
D: Variance
答案: 【 Mean】

3、单选题：
​The Empirical Rule states that:‎
选项：
A: for a bell shaped frequency distribution, approximately 68% of the observations are in the range of plus or minus one standard deviation.
B: for a positively skewed frequency distribution, approximately 68% of the observations are in the range of plus or minus one standard deviation.
C: for a bell shaped frequency distribution, approximately 75% of the observations are in the range of plus or minus one standard deviation.
D: for a positively skewed frequency distribution, approximately 75% of the observations are in the range of plus or minus one standard deviation.
答案: 【 for a bell shaped frequency distribution, approximately 68% of the observations are in the range of plus or minus one standard deviation.】

4、单选题：
‎Which measure of central tendency reports the value that occurs with the highest frequency?‏
选项：
A: Mean
B: Median
C: Mode
D: Standard deviation
答案: 【 Mode】

5、单选题：
‍An example of Chebyshev's Theorem is:‍
选项：
A: for a bell shaped frequency distribution, at least 95% of the observations are in the range of plus or minus two standard deviations from the mean.
B: for a negatively skewed frequency distribution, at least 95% of the observations are in the range of plus or minus two standard deviations from the mean.
C: for any frequency distribution, at least 75% of the observations are in the range of plus or minus two standard deviations from the mean.
D: for a positively skewed frequency distribution, at least 68% of the observations are in the range of plus or minus two standard deviations from the mean.
答案: 【 for any frequency distribution, at least 75% of the observations are in the range of plus or minus two standard deviations from the mean.】

6、单选题：
‌In comparing two different samples of 100 observations, sample "A" has a mean of 10 and a standard deviation of 10. The sample "B" has a mean of 10 and a standard deviation of 50. The two samples are:‎
选项：
A: exactly the same.
B: are centered at 10, but sample "A"s data is more concentrated near the mean.
C: are centered at 10, but sample "B"s data is more concentrated near the mean.
D: positively skewed.
答案: 【 are centered at 10, but sample "A"s data is more concentrated near the mean.】

7、单选题：
‍‌For a distribution, the mean is 5, the median is 15, and the mode is 20. Based on this information, the distribution is:‌‍‌‍‌
选项：
A: positively skewed.
B: negatively skewed.
C: symmetric.
D: bell-shaped.
答案: 【 negatively skewed.】

8、单选题：
‌In a positively skewed distribution, which measure of central tendency is the largest?‎
选项：
A: Mean
B: Median
C: Mode
D: Variance
答案: 【 Mean】

9、单选题：
‏Which of the following statistics is a measure of dispersion?‏
选项：
A: Mean
B: Median
C: Mode
D: Standard deviation
答案: 【 Standard deviation】

10、单选题：
‍What is true about the range?​
选项：
A: Only two values are used in its calculation.
B: It is in different units than the mean.
C: It can be used for nominal data.
D: All values are used in its calculation.
答案: 【 Only two values are used in its calculation.】

第四单元测验

1、单选题：
A dot plot shows:‌‌
选项：
A: the general shape of a distribution.
B: the mean, median, and mode.
C: the relationship between two variables.
D: the interquartile range.
答案: 【 the general shape of a distribution.】

2、单选题：
The test scores for a class of 101 students are computed. What is the location of the test score associated with the third quartile?‏‏
选项：
A: 75%
B: 31
C: 50.0
D: 76.5
答案: 【 76.5】

3、单选题：
‏The test scores for a class of 50 students are computed. What is the location of the test score associated with the second decile?‌
选项：
A: 20%
B: 31
C: 10.2
D: 20.5
答案: 【 10.2】

4、单选题：
‏To summarize a data set with a box plot:‎
选项：
A: two values are required: the 1st quartile and the 3rd quartile.
B: three values are required: the minimum, median, and maximum.
C: four values are required: the minimum, 1st quartile, 3rd quartile, and maximum.
D: five values are required: the minimum, 1st quartile, median, 3rd quartile, and maximum.
答案: 【 five values are required: the minimum, 1st quartile, median, 3rd quartile, and maximum.】

5、单选题：
‌For a data set, the interquartile range is:‌
选项：
A: the difference between the minimum and maximum values.
B: the standard deviation.
C: the difference between the 1st and 3rd quartiles.
D: the skewness of a distribution.
答案: 【 the difference between the 1st and 3rd quartiles.】

6、单选题：
‌For any symmetric distribution:‎
选项：
A: The mean, median, and mode are equal.
B: Compared to the median and mode, the mean is the largest measure of location.
C: Compared to the mean and mode, the median is the largest measure of location.
D: Compared to the mean, median, and mode, the standard deviation is the largest value.
答案: 【 The mean, median, and mode are equal.】

7、单选题：
‌For a data set, the coefficient of skewness is -2.73. We conclude that:​
选项：
A: the mean is larger than the median.
B: the median is larger than the mean.
C: the standard deviation is a less than zero.
D: something is wrong because the coefficient of skewness cannot be less than -1.00.
答案: 【 the median is larger than the mean.】

8、单选题：
The purpose of a contingency table is to summarize:‍‍
选项：
A: two continuous, ratio variables.
B: two discrete, ratio variables.
C: two discrete, nominal or ordinal variables.
D: two discrete, continuous variables.
答案: 【 two discrete, nominal or ordinal variables.】

9、单选题：
​A scatter diagram:‌
选项：
A: graphically portrays the relation