Two students completed an experiment to determine if pesticide use at local farms was causing fish kills in a local pond. The st
eps of the experiment are listed below. Select one location to collect water samples in the pond. Collect a 5-mL water sample at 8 am for two days. Measure the amount of pesticide present in each sample using the same measurement tools. After analyzing their data, the students conclude that pesticide runoff from farms is not causing the fish to die in the pond. Which of these statements best describes why their conclusion is not reliable? 1)The pesticide measurements were the dependent variable.
2)The samples were collected at different times.
3)The samples were only collected for two days.
4)The time of sample collection was not an independent variable.
Answer: 1). The pesticide measurements were the dependent variable.
Explanation:
An independent variable exerts an influence over the dependent variable when changed.
In the given situation, the amount of pesticide is the independent variable which is responsible for killing the fish. Thus the death of fish is the dependent variable nor the amount of pesticides.
1)The pesticide measurements were the dependent variable.
Explanation:
The aim of the experiment was to determine whether the pesticides caused the fish kills. In this scenario, the dependent variable should have been the fish kills and not the pesticides. The amount of pesticides were supposed to be the independent variable.
Independent variables are the variables that change and cause an effect on the test subject or the dependent variable.
The dependent variable is not manipulated, but changes <u>depending</u> on the independent variable.
