Directions  Part 1
1. As a class, look over the “5 Year Average Total Rainfall for La Selva, Costa Rica” data set, looking for a pattern in the data.
2. Answer the pregraphing questions in your science notebooks.
PreGraphing Questions:
 What kind of graph will you use to display the data? Why?
 How should you orient your graph paper?
 Write a meaningful title for your graph.
 Write a label for your x axis.
 Write a label for your y axis.
 What would be a logical scale for your y axis?
3. Graph the data set (by hand or using a computer depending on your teacher’s instructions).
4. Draw a bestfit line through the data points on your graph. You can do this by using a ruler. Draw a straight diagonal line at the point where approximately half of the points are above the line and half are below the line.
5. Discuss any patterns that emerge.
Authentic data for the first graph:
5 Year Average Total Rainfall for La Selva, Costa Rica (mm)
Year

Rain (mm)

1965

5042

1970

4415

1975

4557

1980

4391

1985

3649

1990

4141

1995

4010

2000

4909

2005

4296

Directions – Part 2
1. Graph the maximum rainfall averaged over 5 year time periods for La Selva.
2. Draw a bestfit line on the graph.
3. Discuss any patterns that emerge. Do these data support the guide’s claim?
Authentic data for the second graph:
5 Year Average Maximum Daily Rainfall for La Selva, Costa Rica (mm)
Year

Rain (mm)

1965

159

1970

185

1975

121

1980

180

1985

181

1990

220

1995

170

2000

229

2005

216
