1. Descriptive Statistics and Graphing

2. The Normal Distribution If the frequency (or number) of data points is plotted on the Y-axis, a bell-shaped curve may be produced. # Slow Fast Running Speed of People

3. Skewed Distribution (Not Normal) # Slow Fast Running Speed of People

4. Central Tendency Mean – average Median – middle value Mode – most common value

5. Disadvantages - Mean Influenced by outliers Example- Population estimates of waterfowl on seven lakes: 400 200 220 210 340 250 44,000 Mean = 6,517

6. Disadvantages - Median The central number may not be representative, particularly with small samples. Example: 0, 0, 1, 2, 480, 500

7. Heart Rate (beats per minute) Speed (kilometers per hour) 11 12 13 14 15 16 17 Variables 165 160 155 150 145 140 135 130

8. Number of mammals in a 1.2 ha woodlot in Clinton County, NY Grey squirrel – 8 Red squirrels – 4 Chipmunks – 17 White-footed mice – 26 White-tailed deer – 2 Create a Graph Website: http://nces.ed.gov/nceskids/graphing/

9. Bar Graph - Mammals

10. pH of an a pond in Clinton County, NY on 5/11/05 1:00 AM – 5.2 3:00 AM – 5.1 5:00 AM – 5.1 7:00 AM – 6.0 9:00 AM – 6.6 11:00 AM – 6.9 1:00 PM – 7.0 3:00 PM – 7.0 5:00 PM – 6.6 7:00 PM – 5.9 9:00 PM – 5.3 11:00 PM – 5.2

11. Line Graph - pH

12. Number of bird species observed in 9 woodlots in January 2006 in Clinton County, NY Size of Woodlot (ha)# Bird Species 3.311 813 3.613 14 1.17 1114 7.412 6.614 812

13. Number of bird species observed in 9 woodlots in January 2006 in Clinton County, NY This graph shows a positive relationship between the size of the woodlot and the number of bird species.

14. Number of bird species observed in 9 woodlots in January 2006 in Clinton County, NY This graph shows a negative relationship between the size of the woodlot and the number of bird species.

15. Number of bird species observed in 9 woodlots in January 2006 in Clinton County, NY This graph shows no relationship between the size of the woodlot and the number of bird species.