1. Homework Turn it in now. Has everyone turned in his/her assignment?

2. Answers to 1 ClassesTallyFrequency 22-30IIII4 31-39IIIII5 40-48IIIII5 49-57IIIII5 58-66IIII4 57-75IIII4 76-84IIIIIIIII9 85-93IIII4

3. Answers to 11 ClassesTallyFrequency 37-47IIIII5 48-58IIIIIIIIII10 59-69IIIIIII7 70-80IIIIIIIIIII11 81-91IIIIIIIIII10 92-102IIIIII6 103-113I1

4. Answers to the rest. 2. 3. 76-84 4. 5. 5 6. 7. 10% 8. 9. 52.5% 10. 12. 13. 5 14. 15. 33 16. 17. 22% 18. 19. 30%

5. Grading Write “graded by” and your name to that. Count the number of items correct out of 20.

6. Histograms Statistics Mrs. Spitz Fall 2009

7. Objectives Be able to construct a histogram given information in a problem. Determine the ratio of 2 objects Determine the percentage from a ratio.

8. Assignment Pg. 529 #21-32

9. Definition A bar graph that represents the data in a frequency distribution. The width of the bar represents each class, and the height of the bar corresponds to the frequency of the class.

10. Example 1 A survey of 105 households is conducted and the number of kilowatt hours (kWh) of electricity that are used by each in a one- month period is recorded in the frequency distribution, shown in the figure. The histogram follows.

11. Classes (kWh)Frequency 850-9009 900-95014 950-1,00017 1,000-1,05025 1,050-1,10016 1,100-1,15014 1,150-1,20010

12. Kilowatt Hours Number of Households

13. Example 2 The high temperatures at a ski resort during the 125-day ski season were recorded in a frequency distribution. The histogram for that is shown in the next slide. The temperature was between 15° and 20° on 15 days. Use Figure 11.2 to find the number of days the temperature was 45° or above.

15. Example 4 Use the histogram to find the number of days the temperature was 30° or below.

16. Example 4 Use the histogram to find the number of days the temperature was 30° or below.

17. Strategy Read the histogram Add the frequencies for the classes of 10- 15, 15-20, 20-25, and 25-30 Solution: 2 + 15 + 12 + 18 = 47 So, the number of days the temperature was 30° or below was 47.

18. Assignment Pg. 529 #21-32