1. Lesson 1.1 Interpreting Graphs
Essential Question: How can you analyze data?

2. Before we start…
What would be a good title for a graph of the information? How would you describe the lengths of the bars for each breed of dog?

3. How can you analyze data?
By making different types of graphs: bar graphs, frequency tables, and histograms.

4. What is data?
Facts, numbers, or numerical information

5. What is a bar graph?
A graph in which the lengths of bars are used to represent and compare data

6. Volcanoes The bar graph shows the number of historically active volcanoes in four countries.
Which country has the most active volcanoes?
About how many more historically active volcanoes does Chile have than Mexico?
About how many historically active volcanoes do Canada, Mexico, and the U.S. have altogether?

7. Boston Marathon The bar graph shows the number of male winners of the Boston Marathon by country from 1975 – Which country has the most male winners of the Boston Marathon? Which country has the best male athletes?

8. What is a double bar graph?
A bar graph used to represent two things at once. The graph shows bars in different colors to represent different things.

9. About how many bottled drinks were purchased by eighth graders
About how many bottled drinks were purchased by eighth graders? About how many milk cartons were sold? What type of beverage did seventh graders buy the most? What beverage did eighth graders buy more than seventh graders?

10. The heights, in inches, of 15 players on a basketball team are listed below.
80, 65, 76, 83, 84, 79, 81, 80, 76, 81, 74, 80, 83, 79, 73
How would you group this data? How many data points fit in each group you’ve made?

11. What is frequency?
The number of data values in that interval.

12. What is a frequency table?
Is used to group data values into equal intervals, with no gaps between intervals and no intervals overlapping.

14. Science The numbers of named stars in a group of 34 constellations are listed below. Make a frequency table of the data. 7, 5, 4, 10, 5, 7, 2, 6, 8, 1, 5, 1, 3, 1, 12, 11, 2, 11, 2, 5, 0, 6, 14, 8, 3, 1, 15, 10, 0, 2, 0, 15, 9, 1

15. What is a histogram?
A bar graph that displays data from a frequency table.
Equal sized bars
Length = frequency
No space

16. How do you make a histogram?
Choose equal intervals that cover all of the data values.
Organize the data using a frequency table.
Use the intervals to draw the bars of the histogram.

17. Music Every Sunday morning, a radio station plays a countdown of the top 30 requested songs from the previous week. The table shows the number of weeks that each of the songs on this week’s top 30 have been on the countdown. Make a histogram of the data.

18. Roller Coasters The data show the heights, in meters, of some of the tallest roller coasters in the world. Make a histogram of the data. 66.4, 94.5, 68.3, 115, 62.5, 97, 66.4, 126.5, 63.4, 74.7, 63.4, 70.1, 66.4, 64.9, 63.7, 79, 63.4, 63.1, 62.5, 61.9, 71.6

19. Typing Rates The numbers of words that students in a typing class can type in a minute are listed. Make a frequency table and histogram of the data. 25, 19, 23, 29, 34, 26, 30, 40, 33, 20, 35, 35, 25, 29, 36, 22, 31

20. School Lunches The number of students in your class who brought their lunch to school each day for the past two weeks is given below. Make a frequency table and histogram of the data. 21, 12, 15, 21, 11, 8, 16, 18, 23, 27, 12, 14, 12, 12

21. Traffic Patterns City officials are looking at traffic patterns at a major intersection. They have tracked the average number of cars backed up at the stoplight between 5 A.M. and 6:59 P.M.

22. Butterflies The histogram shows the butterflies spotted in a butterfly garden between 8 A.M. and 8 P.M.

23. How can you analyze data?

24. Ticket Out the Door
What planet has the longest length of day?