Question

make sure to use tails in graphing. use a separate piece of paper to write your captions for problem #2 and problem #3. submit with this worksheet. practice problem #2 background: clams were placed into various temperatures of water. use the information in the data table below in order to create a proper scientific graph and to answer the corresponding questions. 1. what is the dependent variable? 2. what is the independent variable? 3. what is the optimum temperature for clam development? 4. what is the mean number of clams per sample? 5. approximately how many clams would be developing in 10 degree celsius water? 6. what is it called when you make predictions about data not yet recorded, such as the prediction we made in question number 5? use pencil to make graph!

Explanation:

Step1: Identify dependent variable

The variable that changes in response to another is the dependent variable. Here, the number of developing clams changes with water - temperature, so it is the dependent variable.

Step2: Identify independent variable

The variable that is manipulated is the independent variable. Water temperature is being changed, so it is the independent variable.

Step3: Find optimum temperature

The optimum temperature is the one at which the number of developing clams is highest. From the table, at 25°C, the number of developing clams is 140 which is the highest, so the optimum temperature is 25°C.

Step4: Calculate mean number of clams

Sum all the number of developing clams: \(72 + 92+120 + 140+99+72+36+0=631\). There are 8 data - points. Mean=\(\frac{631}{8}=78.875\approx79\).

Step5: Predict for 10°C

Since we have no data for 10°C and we are predicting outside the recorded data range, we note that as temperature decreases from 15°C to 10°C, based on the trend (as temperature decreases from 25°C to 15°C the number of clams decreases), we can assume a lower number. But without a proper model, we can only make a rough estimate. If we assume a linear decrease from 15°C to 10°C similar to the decrease from 20°C to 15°C, we might estimate around 20 (this is a very rough estimate).

Step6: Name of prediction method

Predicting about data not yet recorded is called extrapolation.

Answer:

1. Number of developing clams
2. Water temperature
3. 25°C
4. 79
5. 20 (rough estimate)
6. Extrapolation