Reference no: EM13216473

Dissolved oxygen is oxygen that is trapped in a fluid, such as water. Since many living organism requires oxygen to survive, it is a necessary component of water systems such as streams, lakes and rivers in order to support aquatic life. The dissolved oxygen is measured in units of ppm-or parts per million. Examine the data in Table 4 showing the amount of dissolved oxygen present and the number of fish observed in the body of water the sample was taken from; finally, answer the questions below.

Table 4: Water Quality vs. Fish Population
Dissolved Oxygen (ppm) 0 2 4 6 8 10 12 14 16 18
Number of Fish Observed 0 1 3 10 12 13 15 10 12 13

1. What patterns do you observe based on the information in Table 4? 

The more dissolved oxygen in the water, the more fish is observed in that area of water.

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 there is more dissolved oxygen in the water, there will be more fish present in the area the water sample is taking from.

3. What would your experimental approach be to test this hypothesis?

I would test the dissolved oxygen in different areas of water, keep track of the fish in those areas and compare the results.

4. What would be the independent and dependent variables?

Independent- Dissolved Oxygen
Dependent- Fish

5. What would be your control?
No control

6. What type of graph would be appropriate for this data set? Why? 

A line graph will be appropriate because it supports the hypothesis and provide clear results.

7. Graph the data from Table 4: Water Quality vs. Fish Population table (found at the beginning of this experiment).

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. 

The graph above shows the fish population on the Y (axis) and the dissolved oxygen on the X (axis). The fish population increases in the above graph due to more dissolved oxygen that is found in the body of water. For example: There is 0 dissolved oxygen (ppm) in the water, so there is 0 fish observed.

Exercise 2: Testable Observations
Determine which of the following observations are testable. For those that are testable:
Determine if the observation is qualitative or quantitative
Write a hypothesis and null hypothesis
What would be your experimental approach?
What are the dependent and independent variables?
What are your controls - both positive and negative?
How will you collect your data?
How will you present your data (charts, graphs, types)?
How will you analyze your data?
Observations

1. A plant grows three inches faster per day when placed on a window sill than it does when placed on a on a coffee table in the middle of the living room.

2. The teller at the bank with brown hair and brown eyes is taller than the other tellers.

3. When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she does not exercise and eats fatty foods.

4. The Italian restaurant across the street closes at 9 pm but the one two blocks away closes at 10 pm.

5. For the past two days, the clouds have come out at 3 pm and it has started raining at 3:15 pm.

6. George did not sleep at all the night following the start of daylight savings.