Note: Use R-studio

3. The data BGSall in the alr4 package contains information on n = 136 children in the Berkeley Guidance study, including heights at ages 9 and 18 (HT9 and HT18), and gender (Sex 0 for male, 1 for female). Consider the regression of HT18 on HT9 and the grouping factor Sex (a) Draw the scatterplot of HT18 versus HT9, using a different color for males and females. Comment on the information in the graph about an appropriate mean function for these data. (b)Assuming a first-order model with one binary predictor and one quantitative predictor (parallel regression model) is adequate, estimate a 95% confidence interval for the difference between males and females. For the parallel regression model, this is the difference in the intercepts of the two groups (c) Add the two parallel estimated regression lines to the scatterplot in part (a) with the colors you used in part (a)