Say you cannot force students to attend the after-school program. You expect that no more than half the students in the treatment group will attend the program. Assuming that none of the students in the control group get into the program, what size treatment group will you need in order to measure an effect size of a fifteenth of a standard deviation? This question is based on normalized scores (i.e., the variable pre_mathnorm). Calculate your answer assuming power of 80%, an alpha of 0.05, and no baseline covariates. If using Stata, use the "power" command. If using R, use the twomeans command available as part of the exercise materials.