1. Course 3 9-8 Choosing the Best Representation of Data 9-8 Choosing the Best Representation of Data Course 3 Warm Up Warm Up Problem of the Day Problem of the Day Lesson Presentation Lesson Presentation

2. Course 3 9-8 Choosing the Best Representation of Data Warm Up 1. 6n – 10 = 44 2. 27 = 3  8n 3. 41 + 7x = 8 4. 14 = 6n  16 n = 9 Solve. n = 3 n = 7 n = 5

3. Course 3 9-8 Choosing the Best Representation of Data Problem of the Day A data set has a range of 24 and a mean of 104. If the data set contains three numbers and the highest number is 118, then what are the other two numbers in the data set? 94 and 100

4. Course 3 9-8 Choosing the Best Representation of Data Learn to select the best representation for a set of data.

5. Course 3 9-8 Choosing the Best Representation of Data Data can be represented in several different ways, depending both on the type of data and the message to be conveyed. Type of GraphCommon Use Line graphShows change in data over time. Bar graphShows relationships or comparisons between groups. Circle graphCompares parts to a whole. HistogramShows the frequency of data divided into equal parts. Box-and-whisker plotShows the distribution and spread of data. Line plotShows the distribution of data. Scatter plotShows the relationship of two data sets.

6. Course 3 9-8 Choosing the Best Representation of Data Additional Example 1A: Selecting a Data Display Which graph is a better display of the data on temperature? The line graph shows the change in data over time, so it is the better representation. 40 50 60 70 80

7. Course 3 9-8 Choosing the Best Representation of Data Additional Example 1B: Selecting a Data Display Which graph better shows the relationship between the two data set? The scatter plot shows the relationship of two sets of data, so it is the better representation. 1 2 3 4 5 6 7 8 9 10 11 12 x xxx x x

8. Course 3 9-8 Choosing the Best Representation of Data Check It Out: Example 1A Which graph is a better display of the number of students who own a dog, versus a snake? The bar graph shows a relationship or comparison between groups, so it is the better representation.

9. Course 3 9-8 Choosing the Best Representation of Data Check It Out: Example 1B Which graph is a better display of Macarena’s height? The line graph shows the change in data over time, so it is the better representation.

10. Course 3 9-8 Choosing the Best Representation of Data The Singer family keeps the budget shown below for their monthly expenses. Choose an appropriate data display and draw the graph. Which two categories account for one-fifth of their budget? Groceries$400 Utilities$350 Mortgage$850 Clothing$200 Entertainment$100 Auto$500 Savings$500 Misc.$120 Additional Example 2: Problem Solving Application

11. Course 3 9-8 Choosing the Best Representation of Data Additional Example 2 Continued 1 Understand the Problem You are looking for the best data display and the two categories that take up one- fifth of the Singer family budget. You need to find one-fifth of the whole amount of the budget. Since the data can be organized as a whole, display it in a circle graph. 2 Make a Plan

12. Course 3 9-8 Choosing the Best Representation of Data Additional Example 2 Continued Create a circle graph. For each category calculate the percentage spent. Solve 3 The 2 categories that add up to one-fifth or 20% of the Singer’s budget are auto and entertainment.

13. Course 3 9-8 Choosing the Best Representation of Data Additional Example 2 Continued Look at the table. Entertainment has a budget of $100 and Auto has a budget of $500. So, $600 of the total budget of $3,020, is approximately 20%. The answer is reasonable. Look Back 4

14. Course 3 9-8 Choosing the Best Representation of Data The table shows the number of new students every other year from 1990 to 2004. Choose an appropriate data display and draw the graph. About how many new students were there in 2003? 19904 19928 199414 199616 199822 200030 200242 200450 Check It Out: Example 2

15. Course 3 9-8 Choosing the Best Representation of Data Check It Out: Example 2 Continued 1 Understand the Problem You are looking for the best data display and the number of new students in 2003. You need to find an estimate of the number of new students in 2003. Since the data occurs over time you can use a line graph. 2 Make a Plan

16. Course 3 9-8 Choosing the Best Representation of Data Create a line graph. For each year plot a point and connect the line. Solve 3 You can estimate that in 2003 there were about 48 new students. Check It Out: Example 2 Continued

17. Course 3 9-8 Choosing the Best Representation of Data Look at the table. In 2002 there were 42 new students. In 2004 there were 50 new students, so the answer of 48 new students in 2003 in reasonable. Look Back 4 Check It Out: Example 2 Continued

18. Course 3 9-8 Choosing the Best Representation of Data Lesson Quiz: Part I box-and-whisker plot 1. Which is a better display of the number of miles ran by members of the track team during one week: a box-and-whisker plot or a scatter plot?

19. Course 3 9-8 Choosing the Best Representation of Data Lesson Quiz: Part II 2. The number of boys and girls enrolled in a middle school is shown in the table. Choose an appropriate display for this data and draw the graph. What percent of the students at the middle school are boys? GradeGirlsBoys 6140117 7133145 8130115

20. Course 3 9-8 Choosing the Best Representation of Data Lesson Quiz: Part II Continued 48.3%