7.1 Reading Graphs and Tables 595EXAMPLE (^1) Postal Rates Refer to the table of priority mail postal
rates (from 2009) below. Find the cost of mailing an -pound package by priority
mail to postal zone 4.
StrategyWe will read the number at the intersection of the 9th row and the
column labeled Zone 4.
WHYSince pounds is more than 8 pounds, we cannot use the 8th row. Since
pounds does not exceed 9 pounds, we use the 9th row of the table.
Solution
The number at the intersection of the 9th row (in red) and the column labeled
Zone 4 (in blue) is 13.95 (in purple). This means it would cost $13.95 to mail the
8 12 -pound package by priority mail.
(^8 12)
(^8 12)
(^8 12)
Postage Rate for Priority Mail 2009
Weight
Zones
Not Over Local,
(pounds) 1 & 2 3 45678
Self Check 1
POSTAL RATESRefer to the table
of priority mail postal rates. Find
the cost of mailing a 3.75-pound
package by priority mail to
postal zone 8.
Now TryProblem 17
Read tables.
Data are often presented in tables, with information organized in rowsand columns.
To read a table, we must find the intersectionof the row and column that contains the
desired information.
1
Read bar graphs.
Another popular way to display data is to use a bar graphwith bars drawn vertically
or horizontally. The relative heights (or lengths) of the bars make for easy
comparisons of values. A horizontal or vertical line used for reference in a bar graph
is called an axis.The horizontal axisand the vertical axisof a bar graph serve to frame
the graph, and they are scaled in units such as years, dollars, minutes, pounds, and
percent.
2
1 $4.95 $4.95 $4.95 $4.95 $4.95 $4.95 $4.95
2 4.95 5.20 5.75 7.10 7.60 8.10 8.70
3 5.50 6.25 7.10 9.05 9.90 10.60 11.95
4 6.10 7.10 8.15 10.80 11.95 12.95 14.70
5 6.85 8.15 9.45 12.70 13.75 15.20 17.15
6 7.55 9.25 10.75 14.65 15.50 17.50 19.60
7 8.30 10.30 12.05 16.55 17.30 19.75 22.05
8 8.80 10.70 13.10 17.95 18.80 21.70 24.75
9 9.25 11.45 13.95 19.15 20.30 23.60 27.55
10 9.90 12.35 15.15 20.75 22.50 25.90 29.95
11 10.55 13.30 16.40 22.40 24.75 28.20 32.40
12 11.20 14.20 17.60 24.00 26.95 30.50 34.80