1. 7-3 Histograms Course 2 Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day Lesson Quizzes Lesson Quizzes

2. 7-3 Histograms Warm Up Find the mean, median, mode, and range for the data set. 35, 45, 48, 53, 53, 27, 66, 36, 24 43; 45; 53; 42

3. 7-3 Histograms Problem of the Day Which number does not belong with the others? Why? 81, 64, 36, 27, 49 Possible answer: 27; the others are perfect squares.

4. 7-3 Histograms Prep for MA.7.S.6.2 Construct and analyze histograms…. Sunshine State Standards

5. 7-3 Histograms Vocabulary histogram

6. 7-3 Histograms A histogram is a bar graph that shows the frequency of data within equal intervals. There is no space between the bars in a histogram.

7. 7-3 Histograms The histogram shows the results of a survey asking people the number of hours they sleep per night. Use the histogram to answer each question. Additional Example 1A: Analyzing Histograms A. How many people sleep less than 9 hous per night? Add the number of students in the 3-5 and 6-8 intervals. 23 + 58 = 78 78 people sleep less than 9 hous per night.

8. 7-3 Histograms Additional Example 1B: Analyzing Histograms B. What is the approximate median number of hours people sleep per night? Since 100 people were surveyed, the median is the mean of the 50th and 51st persons’ hours. The 50th and 51st persons’ hours are in the middle of the 6-8 interval. So, a good estimated is 7 hours. IntervalFrequencyRank (by weight) 3-5251-25 6-85326-78 9-111779-95 12-14596-100 Determine the interval of the 50th and 51st people.

9. 7-3 Histograms The histogram shows the results of a local 10K race. Use the histogram to answer each question. Check It Out: Example 1A A. How many runners completed the race in less than 50 minutes? Add the number of runners in the first four intervals. 4 + 6 + 10 + 13 = 33 33 runners completed the race in less than 50 minutes.

10. 7-3 Histograms Check It Out: Example 1B B. What is the approximate median time people ran the race? The 25th and 26th times are in the middle of the 45:00-49:59 interval. So, a good estimated is 47:30. IntervalFrequencyRank (by weight) 33:00-34:59 41-4 35:00-39:59 65-10 40:00-44:59 1011-20 45:00-49:59 1321-33 50:00-54:59 1234-45 55:00-59:59 546-50 Since there were 50 runners, the median is the mean of the 25th and 26th times. Determine the interval of the 25th and 26th times.

11. 7-3 Histograms The table below shows the number of hours students watch TV in one week. Make a histogram of the data. Additional Example 2: Making a Histogram Step 1: Make a frequency table of the data. Be sure to use equal intervals. 6 /// 7 //// //// 8 /// 9 //// 1 // 2 //// 3 //// //// 4 //// / 5 //// /// Number of Hours of TV 1–3 Frequency Number of Hours of TV 15 4–6 17 7–9 17

12. 7-3 Histograms Additional Example 2 Continued Step 2: Choose an appropriate scale and interval for the vertical axis. The greatest value on the scale should be at least as great as the greatest frequency. 1–3 Frequency Number of Hours of TV 15 4–6 17 7–9 17 20 16 12 8 4 0

13. 7-3 Histograms Additional Example 2 Continued Step 3: Draw a bar graph for each interval. The height of the bar is the frequency for that interval. Bars must touch but not overlap. 1–3 Frequency Number of Hours of TV 15 4–6 17 7–9 17 20 16 12 8 4 0 Because the intervals are equal, all of the bars should have the same width. Caution!

14. 7-3 Histograms Additional Example 2 Continued Step 4: Label the axes and give the graph a title. 1–3 Frequency Number of Hours of TV 15 4–6 17 7–9 17 20 16 12 8 4 0 1–3 4–6 7–9 Hours of Television Watched Frequency Hours

15. 7-3 Histograms The table below shows the number of hats a group of students own. Make a histogram of the data. Check It Out: Example 2 Step 1: Make a frequency table of the data. Be sure to use equal intervals. 1–3 Frequency Number of Hats Owned 12 4–6 18 7–9 24 1 // 2 //// 3 //// / 4 //// / 5 //// /// 6 //// 7 //// / 8 //// //// 9 //// //// Number of Hats Owned Frequency

16. 7-3 Histograms Check It Out: Example 2 Continued Step 2: Choose an appropriate scale and interval for the vertical axis. The greatest value on the scale should be at least as great as the greatest frequency. 1–3 Frequency Number of Hats Owned 12 4–6 18 7–9 24 30 25 20 15 10 5 0

17. 7-3 Histograms Step 3: Draw a bar graph for each interval. The height of the bar is the frequency for that interval. Bars must touch but not overlap. 1–3 Frequency Number of Hats Owned 12 4–6 18 7–9 24 30 25 20 15 10 5 0 Check It Out: Example 2 Continued

18. 7-3 Histograms Step 4: Label the axes and give the graph a title. 1–3 Frequency Number of Hats Owned 12 4–6 18 7–9 24 30 25 20 15 10 5 0 1–3 4–6 7–9 Number of Hats Owned Frequency Number of Hats Check It Out: Example 2 Continued

19. 7-3 Histograms Standard Lesson Quiz Lesson Quizzes Lesson Quiz for Student Response Systems

20. 7-3 Histograms Lesson Quiz: Part I Use the histogram to answer each question. 1. How many entrees cost $10 or more? 2. Sarah wants to go to a restaurant where most entrees are less than $10. Should she go to the restaurant whose entrees are represented in the graph? Explain. 29 No; 11 entrees are less than $10, but 29 are more.

21. 7-3 Histograms Lesson Quiz: Part II 4. The list shows the number of laps students ran one day. Make a histogram of the data. 4, 7, 9, 12, 3, 6, 10, 15, 12, 5, 18, 2, 5, 10, 7, 12, 11, 15 Number of Students Number of Laps Run 10–14 0–4 5–9 8 6 4 2 0 15–19 Number of Laps

22. 7-3 Histograms Lesson Quiz for Student Response Systems 1. How many students scored below 80? A. 6 B. 13 C. 19 D. 37

23. 7-3 Histograms Lesson Quiz for Student Response Systems 2. How many students took the final exam? A. 20 B. 50 C. 60 D. 100