In a cumulative percent frequency distribution the

20. In a cumulative percent frequency distribution, the last class will have a
cumulative percent frequency equal to
a. one
b. 100
c. the total number of elements in the data set
Answer: b
21. Data that provide labels or names for categories of like items are known as
22. A tabular method that can be used to summarize the data on two variables
simultaneously is called
23. A graphical presentation of the relationship between two variables is
24. A histogram is said to be skewed to the left if it has a
a. longer tail to the right
b. shorter tail to the right
c. shorter tail to the left
d. longer tail to the left
Answer: d

Descriptive Statistics: Tabular and Graphical Presentations 5
25. When a histogram has a longer tail to the right, it is said to be
26. In a scatter diagram, a line that provides an approximation of the relationship
between the variables is known as
Exhibit 2-1
The numbers of hours worked (per week) by 400 statistics students are shown below.
Number of hours Frequency
0 - 9 20
10 - 19 80
20 - 29 200
30 - 39 100
27. Refer to Exhibit 2-1. The class width for this distribution
28. Refer to Exhibit 2-1. The number of students working 19 hours or less
a. is 80
b. is 100
c. is 180
d. is 300
Answer: b
29. Refer to Exhibit 2-1. The relative frequency of students working 9 hours or less
30. Refer to Exhibit 2-1. The percentage of students working 19 hours or less is

6 Chapter Two
31. Refer to Exhibit 2-1. The cumulative relative frequency for the class of 20 - 29
32. Refer to Exhibit 2-1. The cumulative percent frequency for the class of 30 - 39
is
a. 100%
b. 75%
c. 50%
d. 25%
Answer: a
33. Refer to Exhibit 2-1. The cumulative frequency for the class of 20 - 29