0.3. This problem focuses on the impact of a computer assisted learning program (cal) on educational outcomes. This program is a computer-assisted learning program where children in grade 4 are offered two hours of shared computer time per week during which they play games that involve solving math problems whose level of difficulty responds to their ability to solve them. The data file "baroda.dta" contains the data. Use the \"read_dta" function from the \"haven" package to read the file in R. Observations are at the child level. "cal\" indicates whether the child was selected in the cal program. Implementation of the program was intended to be randomised among children in grade 4. The main outcome of interest is whether the intervention resulted in improvement in math test scores. Performance in math was measured using pre_mathnorm before implementation, and post_mathnorm, after the intervention. The tests scores have been normalised to be standardised variables, as indicated by variable names. Note of caution: the program is implemented only in grade 4 (grade is measured by the variable llstdll') (i) Discuss the potential sources of selection bias and the direction of the bias for such an education program. (1 mark) (ii) Using the standardised variables for tests scores in math, check whether the randomisation has performed well. (1 mark) (iii) Estimate the ATE of the program in math. Can we interpret the effect as causal? (1 mark) (iv) Estimate the effect of the program on whether children improved their math scores relative to what would have been expected relative to their initial scores. In order to do this, estimate a specification in which the dependent variable is improvement in math scores and in which you control for initial math scores. Why would you want to do this? What can you conclude with respect to the likely effect of the program on math outcomes? (1 mark)