Page 20 - Appplied Mathematics for the Petroleum and Other Industries, 5th Edition

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3

Number Relations

OBJECTIVES

Upon completion of chapter 3, the student will be able to—
1. Discuss the relation of percent to the whole, and calculate a given percent
of a given number.
2. Change percent to hundredths and hundredths to percent.
3. Solve for base, rate, or percentage in percent problems.
4. Read, write, and determine ratios of one quantity to another.
5. Solve problems involving direct proportion.
6. Solve problems involving inverse proportion, including pulley and gear
ratio problems.
7. Find the average, or mean, of a set of statistics.
8. Find the median and mode in a body of data.
9. Use reference tables for extracting information.
10. Interpolate additional numerical data from information given in a table.
11. Name the parts of a table and construct a table from given data.
12. Extract approximate statistics from a graph, noting trends.
13. Determine the best method for depicting numerical information.
14. Plot and draw a bar graph, a line graph, and a circle graph.

INTRODUCTION
Petroleum Extension-The University of

and decisions. Charts, graphs, and the like can show trends, illustrate deductions,
and help make decisions based on numerical facts. Common relationships are
percentage, ratio, proportion, average, mean, median, and mode. Graphs, tables,
and charts are often used to depict relationships.

PERCENTAGE

Percent expresses a proportion of an amount in hundredths. Percent means for
or out of each hundred. The symbol for percent is % and it expresses quantity
Number relationships, charts, graphs, and tables can help in making calculations Texas at Austin
in relation to a whole. It is only used specifically and always with a number. For
example:
26 percent = ²⁶⁄₁₀₀ = 26% = 0.26.
14½ percent = ¹⁴⁵⁄1,000 = 14.5% = 0.145.
To change from percent to hundredths, shift the decimal point two places to
the left and drop the percent symbol. For example, to change 32% to hundredths,
drop the % symbol and move the decimal point two places to the left, which
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