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Homework. Turn it in now. Has everyone turned in his/her assignment?. Answers to 1. Answers to 11. 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%. Answers to the rest. Grading. Write “graded by” and your name to that.
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Homework • Turn it in now. Has everyone turned in his/her assignment?
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% Answers to the rest.
Grading • Write “graded by” and your name to that. • Count the number of items correct out of 20.
Histograms Statistics Mrs. Spitz Fall 2009
Objectives • Be able to construct a histogram given information in a problem. • Determine the ratio of 2 objects • Determine the percentage from a ratio.
Assignment • Pg. 529 #21-32
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.
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.
Number of Households Kilowatt Hours
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.
Example 4 • Use the histogram to find the number of days the temperature was 30° or below.
Example 4 • Use the histogram to find the number of days the temperature was 30° or below.
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.
Assignment Pg. 529 #21-32