Kaylee wants to test her hypothesis that she performs better on tests after getting more sleep. in which way will she best be able to do this? by analyzing her test scores when she gets the same amount of sleep by asking her friends if sleep affects their test scores by analyzing her average test scores after nights with different amounts of sleep by reading online about the relationship between sleep and test scores

The correct answer is: by analyzing her average test scores after nights with different amounts of sleep.

This is the best way to approve her hypothesis, because she can compare the results of the tests influenced by different amounts of sleep.

The independent variable (the one that is changed by the scientist) in this hypothesis would be hours of sleep. The dependent variable (the one that is observed and that responds to the change made by the independent variable) would be result of test.

i think the answer would be d