1. Bellwork

2. Choosing a Data Display Tell whether the data are qualitative or quantitative. a.prices of used cars at a dealership quantitative b.b. jersey numbers on a basketball team

3. c. lengths of songs played at a concert d. zodiac signs of students in your class

4. You are comparing the average temperature for Denver, CO., Nashville, TN., Columbus, OH., and New Orleans, LA. Which type of graph would be best to represent the data? Circle Line Bar Stem-and-leaf plot

5. Return

8. Stem Leaf 678678 8 3 6 1 Return

10. EXAMPLE 1 Choosing an Effective Display Stamps Which graph is more effective in comparing the percent of people who prefer sports stamps to the total number of people?

11. EXAMPLE 1 Choosing an Effective Display ANSWER The circle graph shows the whole, so it is more effective in showing that 50% of the people chose sports as their favorite stamp subject.

12. EXAMPLE 2 Making an Appropriate Display Sunglasses You ask 20 people at a beach how many pairs of sunglasses they own. The list below shows their responses. Make a data display that shows the spread of data. 0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 6, 6, 10

13. EXAMPLE 2 Making an Appropriate Display SOLUTION You can use a box-and-whisker plot to show the spread of data. The box tells you that about half of the people own 2 to 4 pairs of sunglasses.

14. EXAMPLE 3 Choosing an Appropriate Display Weather The data displays organize the daily high temperatures during a recent month in Boston, Massachusetts. Which display can you use to find the median high temperature? 3 4 5 7 6 8 Key: 3 6 0 0 3 4 2 Weather 1 3 0 3 5 4 3 2 5 4 3 7 6 5 8 6 5 9 6 7 9 8 8 9 6 = 36 º F

15. EXAMPLE 3 Choosing an Appropriate Display SOLUTION You can use the stem-and-leaf plot to find the median high temperature, 56ºF, because it displays the data in order. The circle graph does not display the individual temperatures.

16. GUIDED PRACTICE 1. In Example 1 on page 719, suppose you want to compare people preferring art stamps to people preferring animal stamps. Which graph is more effective? Explain. for Examples 1, 2, and 3 What If?

17. GUIDED PRACTICE ANSWER bar graph; The data is in distinct categories. for Examples 1, 2, and 3 1. In Example 1 on page 719, suppose you want to compare people preferring art stamps to people preferring animal stamps. Which graph is more effective? Explain. What If?

18. GUIDED PRACTICE 2. You record the temperature (in degrees Fahrenheit) at noon for seven days in a row. The data are listed below. Which data display would you use to show how the temperature changed during that time? Make the display. for Examples 1, 2, and 3 50ºF 42ºF 30ºF 32ºF 45ºF 55ºF 50ºF

19. GUIDED PRACTICE for Examples 1, 2, and 3 ANSWER line graph; See margin for art. 2. You record the temperature (in degrees Fahrenheit) at noon for seven days in a row. The data are listed below. Which data display would you use to show how the temperature changed during that time? Make the display. 50ºF 42ºF 30ºF 32ºF 45ºF 55ºF 50ºF

21. Appropriate Data Displays Which graph would be most appropriate to show the method of travel used by most people? Which graph compares the number of people who ride the bus to the entire population? BrainPop: Graphs

22. Appropriate Data Displays Which graph would be best to show the change in average temperatures?

23. When would I use… a Circle graph a Line graph a Line plot / Frequency table a Bar graph 23452345 XxXx XxXx XXxxXXxx XxxXxx

24. Match the display with it’s purpose Line graphTo compare data in different categories Circle graphTo organize data in numerical order Bar graphTo Show change over time Stem – and – Leaf To compare parts to a whole Line PlotTo count the number of events