# Natural Science Physics

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• Published : May 22, 2013

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Exercise 1: Data Interpretation
Table 1: Water Quality vs. Fish Population
Dissolved Oxygen024681012141618
Number of Fish Observed01310121315101213

1. What patterns do you observe based on the information in Table 1? The number of fish will increase as the number of dissolved oxygen in water is added in multiples of two ppm. However, the table shows a roller coaster effect where the peak of dissolved oxygen water of 12 ppm reaches 15 observed fish then drops to 10 observable fish after adding two more dissolved oxygen water. This seems to go in a linear pattern however not enough information to determine why the sudden drop after the peak.

2.Develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of water. If the added dissolved oxygen in water is increased then the greater the number of fish will be observed.

3.What would your experimental approach be to test this hypothesis? My experimental approach would be is to have dissolved oxygen water at hand pouring after a certain amount and time to observe the fish that is gathering at a certain area in the water. Recording my observation in a controlled environment is the key with the safety in mind.

4.What are the independent and dependent variables?
The independent variable is the dissolved oxygen water and the dependent variable is the amount of fish that appears.

Water absent of dissolved oxygen, temperature, humidity, the current if plausible.

6.What type of graph would be appropriate for this data set? Why? A line graph is the appropriate data set to show the increases and decreases of observed fish to appear at a certain level of dissolved oxygen water.

7.Graph the data from Table 1: Water Quality vs. Fish Population (found at the beginning of this exercise). You may use Excel, then “Insert” the graph, or use another drawing program. You may also draw it neatly by hand and scan your drawing. If you choose this option, you must insert the scanned jpg image here.

8.Interpret the data from the graph made in Question 7.
As you add increments of dissolved oxygen water the population of fish increases. However, once it reaches a certain peak the population dips then returns back up. It is uncertain why this happened but all I can say is that I need more information of whether the change was influenced by other variables and will the population of fish stay constant if the added dissolved water increases further on.

Exercise 2: Testable Observations

Determine which of the following observations (A-J) could lead to a testable hypothesis. For those that are testable:
Write a hypothesis and null hypothesis
What would be your experimental approach?
What are the dependent and independent variables?