1. Histograms and Line Graphs

2. Histogram A type of bar graph Separates information into categories The bars are connected *Uses intervals You need a frequency table to make a histogram

3. Steps to Take: First, put the data in order from least to greatest. Second, determine the interval you need to use. Third, make a frequency table to organize your information. Fourth, make your histogram.

4. Example: 40,13, 35, 27, 41, 34, 21, 37, 40, 12, 33 Step 1: ◦ 12,13, 21, 27, 33, 34, 35, 37, 40, 40, 41 Step 2: ◦ Use intervals of 10 Step 3: ◦ IntervalFrequency 0-90 10-192 20-292 30-394 40-493

5. Example 1 (continued) 010203040 INTERVAL FREQUENCY 1 2 3 0 4 50

6. Problems: Make a histogram with the following data: 13, 24, 12, 6, 9, 30, 37, 34, 16, 13, 4, 8, 0, 20 Make a histogram with the following data: 106, 110, 90, 83, 79, 99, 110, 107, 105, 103, 124, 148

7. Line Graph Graph with a line *Shows change over time Points are placed on a graph and connected by (straight) line segments

8. Steps to Take: First, organize the data into a chart. Second, place the change on the vertical axis and the time on the horizontal axis. Third, determine an appropriate interval for both. Fourth, plot your points. Fifth, connect each point to the next with a line segment.

9. Example: A child recorded his height since 2007. In 2007, he was 50 inches tall. In 2008, he was 54 inches tall. In 2009, he was 56 inches tall. In 2010, he was 60 inches tall. In 2011, he grew to 65 inches tall. In 2012, he was 68 inches tall. Step 1 ◦ YearHeight 200750 200854 200956 201060 201165 201268

10. Example: Step 2: Years will go on bottom and height will go on the left. Step 3: Years will go up by 1. Height will go up by 10.

11. Example: Steps 4 and 5 Year 200720082009201020112012 Height (in inches) 0 10 20 30 40 50 60 70

12. Problems Make a line graph with the following data: In 1990, there were 40 animals at the zoo. In 1995, they had 56 animals. In 2000, the number had dropped to 23 due to a hurricane the previous year. In 2005, a new shipment of koalas boosted the number to 43. In 2010, the number of animals was all the way up to 62.

13. Problems Mr. Plyler has taught several different class sizes over the past eight years. In 2005, he had 32 students. The next year he had 30. The following year he had 28. When he moved to Humboldt in 2008, he had 25. In 2009, he had 22. In 2010, his class size dropped to 18. However, in 2011, due to a budget cut, his class sizes rose to 23. Then he moved to Medina in 2012 and has a class size of 28. Make a line graph with this information.