Q1. Use the following data set for the PS5: mars <- read.csv("http://ryantgodwin.com/data/mars.csv") Using OLS, estimate the "returns to education". That is, estimate how much income increase (on average) due to an additional year of education. Interpret your estimates results. use R studio to get the dataset by pasting the code above.

Q2. Explain while the additional demographic variables (e.g. age, gender, height) are needed in the regression, even though you are only interested in "education". Comments on your estimated results. Do you found any differences with the calculated results for Q1?

Q3. Test the null hypothesis that the returns to education are zero. Comments on your findings?

Q4. Paste your R codes. Organize your codes so that other people outside the class can easily understand what you are trying to calculate/estimate.

(PLEASE PROVIDE ALL THE R CODES YOU USED SO THAT I CAN PRODUCE THE SAME OUTPUT).