Statistical Graphs: A Problem-Solving

ToolSection 12.5

2

ExampleThe following data show the average amount of money spent on health care by persons under age 25:

1 425 2 445

3 5514 5045 530

Graph the data using 1–5 as the years and 400–600 as the amounts of $50 intervals. 3

Graph

 

1 2 3 4 5400

450

500

550

600

425

445

551

504

530

Average Amount of Money Spent on Health Care by Persons Under 25

Am

ount

(do

llars

)

Year 4

Example The double bar graph shows the production

costs and gross income (in thousands) for a company. Approximate the percent of gross income that goes to production costs for each year.

5

Solution

a. For 1998:

b. For 1999:

c. For 2000:

%61%100180

110

%45%100200

90

%46%100380

175

6

Example A recent survey of households showed that

more people planned to make major purchases this year. The following table gives the results of the survey. Use side-by-side vertical bar graphs comparing the percent of consumers planning to buy each of the items with the percent who bought each item last year.

Bought Last Year Plan to Buy This Year

Home 101 151

Car 326 390

Appliance 486 553

RV's 62 100

None 1432 1490 7

Bought Last Year Plan to Buy This Year

Home

Car

Appliance

RV's

SolutionBought Last Year Total = 2407Plan to Buy this Year Total = 2684

Bought Last Year Plan to Buy This Year

Home

Car

Appliance

RV's

0.042 = 4.2%

0.135 = 13.5%

0.202 = 20.2%

0.026= 2.6%

101/2407

326/2407

486/2407

62/2407

151/2684

390/2684

553/2684

100/2684

0.056 = 5.6%

0.147 = 14.7%

0.206 = 20.6%

0.037 = 3.7%8

Graph

9

Example

Construct a pie chart depicting the percentage of American adults interviewed who drink caffeinated beverages on a daily basis.

• 1-2 cups per day 34• 3-4 cups per day 15• 5-6 cups per day 10• 7+ cups per day 8• None 27 Total: 94

10

SolutionCups per Day Percentage

1-2 cup 34 34/94

3-4 cups 15 15/94

5-6 cups 10 10/94

7+ cups 8 8/94

None 27 27/94

Cups per Day Percentage

1-2 cup 34 0.36= 36%

3-4 cups 15 0.16 = 16%

5-6 cups 10 0.11 = 11%

7+ cups 8 0.09 = 9%

None 27 0.29 = 29%11

Graph

12END