Question

Imagine that you want to compare a new diet for tadpoles that are reared in the laboratory to the traditional laboratory diet of boiled lettuce. You want to decide if the new diet will be associated with an increase in the average weight of the tadpoles. The new diet is a meat-based commercial fish food. In your experiment you keep all other factors, such as tadpole density, temperature, pH, amount of food, etc., constant. The only difference between your control and experimental groups is the type of food the tadpoles receive. Write a null hypothesis for this experiment: Write an alternate hypothesis for this experiment: What is the independent variable? What is the dependent variable? Would you want to test only one pan of tadpoles fed lettuce, and only one pan of tadpoles fed meat? Why or why not? After you weighed your tadpoles at the end of the experiment, how would you determine if the type of diet significantly affected tadpole size?

Answer 1

Null Hypothesis : There is no effect on the weight of tadpoles when the new diet is introduced.

Alternative hypothesis: There is an effect on the weight of tadpoles when the new diet is introduced.

Independent variable : new diet and lettuce diet

Dependent variable : weight of tadpoles

No, we want to compare both tadpoles with two different diet because we want to compare the effect of both the diet on the weight of tadpoles.

We could significance test like Chi square test to know the type of diet significantly affected tadpole size.