大学MOOC 保险统计(对外经济贸易大学)1451648235 最新慕课完整章节测试答案

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: 【 4】

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 o