Scientific calculations - interpreting photosynthesis test results
The table shows a set of results obtained by students investigating the effect of light intensity on photosynthesis. They varied the distance of the plant from the light source.
In the table below, the Rate of photosynthesis = Number of bubbles produced per minute.
| Distance | Rate |
| 10 cm | 120 |
| 15 cm | 54 |
| 20 cm | 30 |
| 25 cm | 17 |
| 30 cm | 13 |
| Distance | 10 cm |
|---|---|
| Rate | 120 |
| Distance | 15 cm |
|---|---|
| Rate | 54 |
| Distance | 20 cm |
|---|---|
| Rate | 30 |
| Distance | 25 cm |
|---|---|
| Rate | 17 |
| Distance | 30 cm |
|---|---|
| Rate | 13 |
If we draw a graph of this data:
Question
From the graph, suggest the rate of oxygen production at 18 cm from the light source.
40 bubbles per minute.
Using the graph: