The number of class intervals in a frequency distribution is usually between （）.

单项选择题A cumulative frequency polygon is also called （）.

A.an ogive
B.a histogram
C.a frequency polygon
D.a stem and leaf plot

单项选择题If the individual class frequency is divided by the total frequency, the result is the （）.

A.midpoint frequency
B.cumulative frequency
C.stem and leaf plot
D.relative frequency

单项选择题If data are grouped into intervals and the number of items in each group is listed, this could be called a （）

A.ogive
B.histogram
C.frequency distribution
D.stem and leaf plot

单项选择题Which of the following is not the goal of descriptive statistics?（）

A.Summarising data
B.Displaying aspects of the collected data
C.Reporting numerical findings
D.Estimating characteristics of the population

单项选择题A student achieves an 82 on the first test in a statistics course. From this, she assumes that her average at the end of the semester (after other tests) will be about 82. This is an example of （）.

A.descriptive statistics
B.inferential statistics
C.nonparametric statistics
D.wishful thinking

单项选择题Which of the following statements is not true？（）

A.One form of descriptive statistics uses graphical techniques
B.One form of descriptive statistics uses numerical techniques
C.In the language of statistics，the term population refers to a group of people
D.Statistical inference is used to draw conclusions or inferences about characteristics of populations based on sample data

单项选择题Descriptive statistics deals with methods of（）

A.organising data.
B.summarising data
C.presenting data in a convenient and informative way
D.doing all of the above

单项选择题Simon Arnett, Director of Human Resources, is exploring the causes of employee absenteeism at Buderim Bottling during the last operating year (1 January 2005 to 31 December 2005). Personnel records of 50 employees are selected for analysis. (The plant employs 250.) For this study, the average number days absent for these 50 employees is a （）.

A.population
B.sample
C.parameter
D.statistic

单项选择题A summary measure that is computed from a sample to describe a characteristic of the population is called（）

A.a parameter
B.a statistic
C.a population
D.Both A and C are correct，since they are the same

单项选择题Simon Arnett, Director of Human Resources, is exploring the causes of employee absenteeism at Buderim Bottling during the last operating year (1 January 2005 to 31 December 2005). The average number of absences per employee, calculated from the personnel data of all employees, is a （）.

A.population
B.sample
C.parameter
D.statistic