The width of each bar in a histogram corresponds to

2. The width of each bar in a histogram corresponds to the
a) differences between the boundaries of the class.
b) number of observations in each class.
c) midpoint of each class.
d) percentage of observations in each class.
TABLE 2-3
Every spring semester, the School of Business coordinates with local business leaders a luncheon for
graduating seniors, their families, and friends. Corporate sponsorship pays for the lunches of each of the
seniors, but students have to purchase tickets to cover the cost of lunches served to guests they bring with
them. The following histogram represents the attendance at the senior luncheon, where X is the number of
guests each graduating senior invited to the luncheon and f is the number of graduating seniors in each
category.

17
152
85
18
3
0
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5
Guests per Student
3. Referring to the histogram from Table 2-3, how many graduating seniors attended the luncheon?
A survey was conducted to determine how people rated the quality of programming available on television.
Respondents were asked to rate the overall quality from 0 (no quality at all) to 100 (extremely good
quality). The stem-and-leaf display of the data is shown below.
Stem Leaves
3 24
4 03478999
5 0112345
6 12566
7 01
8
9 2
4. Referring to Table 2-4, what percentage of the respondents rated overall television quality with a rating
of 80 or above?
The following are the durations in minutes of a sample of long-distance phone calls made within the
continental United States reported by one long-distance carrier.
Relative
Time (in Minutes) Frequency
0 but less than 5 0.37
5 but less than 10 0.22
10 but less than 15 0.15
15 but less than 20 0.10
20 but less than 25 0.07
25 but less than 30 0.07
30 or more 0.02
5. Referring to Table 2-5, what is the width of each class?
6. Referring to Table 2-5, if 10 calls lasted 30 minutes or more, how many calls lasted less than 5
minutes?
a) 10