1. Section 7.2 Interpreting Numbers
Marketing Essentials
n Chapter 7 Basic Math Skills
Section 7.2 Interpreting Numbers

2. Interpreting Numbers SECTION 7.2
What You'll Learn
How to use a calculator to solve math problems
The procedure used to convert percentages to decimals and decimals to percentages
The ways to read different types of graphs used to present mathematical data

3. Interpreting Numbers SECTION 7.2
Why It's Important
Most jobs in marketing require the use of a calculator. Many require using a computer to generate graphic presentations. You will improve your skill level on the calculator as you study this section. You will also gain a greater understanding of graphs and charts.

4. Interpreting Numbers SECTION 7.2 percent bar graph line graph
Key Terms
percent
bar graph
line graph
circle graph
pie chart

5. Interpreting Numbers SECTION 7.2 Using a Calculator
Nearly everyone in marketing and business uses calculators. Besides simply knowing which buttons to press, you will be expected to work with accuracy, know how to work with fractions and amounts of money, and have an understanding of how the calculator computes with multiple operations.

6. Interpreting Numbers SECTION 7.2 Estimate, Then Operate
"Guess and Check" Estimate the answer, then enter the problem in the calculator, then check the calculator's answer against your estimate.
This is important because you may make errors when entering numbers or even press the wrong operation key.

7. Interpreting Numbers SECTION 7.2 How to Make Entries
Disregard leading zeros to the left of the decimal point and final zeros after the decimal point.
When dealing with fractions, first convert the fractions to decimal form.
Remember that most calculators perform calculations in the order they are entered.

8. Interpreting Numbers SECTION 7.2 Percentages
Percent means parts per hundred. To write a whole number or a decimal number as a percent, multiply it by 100, or move the decimal point two places to the right.
0.70 = 0.7 x 100 = 70% or = 70%
0.05 = x = 5% or = 5%
= x = % or = 250%
Move the decimal point
Two places to the right.
Write 0s as needed.

9. Interpreting Numbers SECTION 7.2 Converting Fractions to Percentages
To write a fraction as a percent, first convert the fraction to decimal form, then multiply by 100. If there is a whole number, add it to the converted fraction before multiplying by 100.
3/8 = 3 ÷ 8 x 1 =
37.5 = 37.5%
4 2/3 = 2 5 + 4
440 = 440%

10. Interpreting Numbers SECTION 7.2 Converting Percentages to Decimals
Change a percent to a decimal number by dividing by 100, or by moving the decimal point two places to the left.
Move the decimal point
two places to the left.
24.8% = 24.8 ÷ 100 = or 24.8% = 0.248
0.5% = ÷ = or % =
Write 0s as needed.

11. Interpreting Numbers SECTION 7.2 Percent Problems
To find a percent of a number, multiply the decimal equivalent of the percent by the number. Use the following steps:
1. Estimate the answer.
2. Translate the problem into a math statement.
3. Do the calculations.
4. If necessary, round money amounts to the nearest cent.
5. Check your answer.

12. Interpreting Numbers SECTION 7.2 Reading Charts and Graphs
Graphs are a way of presenting numbers in a way that is easier to understand than a long series of numbers. Usually a graph shows the relationship between two kinds of data, or statistical information. There are three basic kinds of graphs:
bar graphs
line graphs
circle graphs

13. Interpreting Numbers SECTION 7.2 Bar Graphs
A bar graph is a drawing made up of parallel bars whose lengths are proportional to the qualities being measured.

14. Interpreting Numbers SECTION 7.2 Compact Disc Sales By Age Group
According to this bar graph, how did the oldest customers compare with the youngest in terms of purchases?

15. Interpreting Numbers SECTION 7.2 Line Graphs
A line graph uses a line that joins points representing changes in a variable quantity, usually over a specific period of time. Line graphs are very useful for charting sales, prices, profits, or output.

16. Interpreting Numbers SECTION 7.2 Compact Disc Sales
Line graphs chart change over time—in this case, the change in sales figures over a period of 12 months. How would you summarize the progression of sales over the course of the year?

17. Interpreting Numbers SECTION 7.2 Circle Graphs
A circle graph is a geometric representation of the relative sizes of the parts of a whole. It is better known as a pie chart.
Businesses often choose such a graph to compare things like the costs of different aspects of manufacturing or the ways income from sales is used by a company.

18. Interpreting Numbers SECTION 7.2
Retail Price Distribution—Compact Discs
This circle graph shows a whole, the price of a compact disc divided into parts. Which two price components account for more than half of the price of a CD?

19. Reviewing Key Terms and Concepts
ASSESSMENT
7.2
Reviewing Key Terms and Concepts
1. Use a calculator to find the decimal equivalent of 1/7.
2. What is the decimal equivalent of percent?
3. What are three forms of graphic representation?

20. ASSESSMENT Thinking Critically 7.2
A market researcher plans to present data about purchases of colas by age group. She can't decide whether to use a bar graph or to list her groups on a chalkboard in order of size. What should she do, and why?

21. Marketing Essentials
End of Section 7.2