Isabel conducted a study to evaluate if there was an effect of baby formula on total fat in 1 year old babies. In this study, she had two groups, one group were babies fed with baby formula only, the other group were breast fed babies. Which option corresponds to the best model or the best models to analyze the data?

1) Classical Regression Model

2) t-test for paired samples

3) t-test for independent samples

4) Options 1 and 3 would be the best choices