A.a frequency polygon

B.a stem and leaf plot

C.an ogive

D.a histogram

正确答案：an ogive

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

A.3 and 5

B.1 and 25

C.7 and 9

D.5 and 15

正确答案：5 and 15

5、One advantage of a stem and leaf plot over a frequency distribution is that（）.

A.the class midpoints are used as the leaf

B.the class midpoints are used as the stem

C.it contains more class intervals

D.the values of the original data are retained

正确答案：the values of the original data are retained

6、One rule that must always be followed in constructing frequency distributions is that（）.

A.each data point can only fall into one class

B.the width of each class is equal to the range

C.the number of classes must be less than 10

D.the number of intervals must be an odd number

正确答案：each data point can only fall into one class

7、Which of the following is best to show the percentage of a total budget that is spent on each category of items？

A.histogram

B.ogive

C.stem and leaf chart

D.pie chart

正确答案：pie chart

8、A cumulative frequency distribution would provide（）.

A.a running total of the frequencies in the classes

B.the proportion of the total frequencies which fall into each class

C.a very cloudy picture of the frequencies

D.a graph of a frequency distribution

正确答案：a running total of the frequencies in the classes

9、The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developeD.Class IntervalFrequency20-under 403040-under 604560-under 808080-under 10045

What is the cumulative frequency of the third class？

A.75

B.80

C.0.40

D.155

正确答案：155

10、The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developeD.Class IntervalFrequency20-under 403040-under 604560-under 808080-under 10045

What is the approximate range of the number of phone calls arriving each hour？

A.20

B.200

C.100

D.80

正确答案：80

第三章单元测试

1、Simon Arnett， Director of Human Resources， is exploring employee absenteeism at the Buderim Bottling during the last operating year.A sample of six personnel records produced the following dat