Susan wanted to know if aerobic exercise caused more weight loss than just walking. susan had her experimental group do aerobic exercise for 20 minutes, 4 days a week. she weighed each subject before the experiment started and again 3 months into the experiment. the independent variable in her experimental research was

Independent variable : Anaerobic Exercise

Step-by-step explanation:

The dependent variable is known as the variable of interest or "Y" and usually the independent variables are expressed by "X".

The independent variable is the "variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable"

For this case our independent variable would be the  anerobic exercise, since we want to se the effect of the exercise on the weigth loss, so then our dependent variable would be th weigth loss.

And for this case we can check the hypothesis with a paired t-test if we use the same individuals.

A paired t-test is used to compare two population means where you have two samples in which observations in one sample can be paired with observations in the other sample. For example if we have Before-and-after observations we can use it.

(D)

Step-by-step explanation:

The given equation is:

Combining the like terms, we get

which is the required correct step for solving the given equation.

therefore, again combining the like terms, we get

thus, option D is correct.